Thanks thats what I needed a good start. Have my list made will keep u posted 
have a good one man
have a good one man70mm Or 75mm Throttle Body?
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reading this thread was comforting seeing a new kid getting lots of good advice! on corral all he would of got was bashed ......btw im running a 70mm accufab on a cobra intake on a 333 stroker afr 185 head almost making 400rwhp
First know what you want to do and make a plan to get there.
Far too many people put a dab of this and a dollop of that, and then wonder why the car doesn't run worth beans. Then they think off the shelf computer chips will fix their mismatched parts problem. It won't You have to have a plan for what kind of performance you want: Hot street. Street/Strip, Pure strip, Autocross or Road course. Each one requires a different strategy and a different set of components.. Mismatch the components and you’ll have a car that falls flat on its face when you demand performance.
Everyone thinks HP! HP! HP! and thinks that peak HP is what they need. Peak HP is great for a drag strip car when it has the proper gears and tires to get the car up into the high RPM range where it develops that high peak HP near the finish line. On a street car, that strategy will have Honda Accords outrunning you, because you will never get the engine RPMs high enough without running over everything in your path.
Here’ the strategy: Always remember that there are some tradeoffs in any engine combination. Most of us don’t have enough money to “have it all” as if it was possible by some masterful combination of parts and tuning.
The following recommendations are for 5 Speed Manual transmission cars without NO2 or pressurized induction, stock short block.
1.) Hot street: Broad flat torque curve, high velocity airflow in the intake and heads for best throttle response. Gears suitable for reasonable gas mileage and long road trips without excessive engine RPMs. Stand on the gas pedal from a rolling start to squeeze into that gap in traffic in front of you, and it jumps quick and hard to get you there. Max RPM’s are 5200-5500 RPM for best power. Lopey cams may sound cool, but run poorly in a low RPM street environment.
Use stock cam, stock, GT40 or mildly ported stock heads, Cobra or Explorer/GT40 intake, advanced timing, stock 19 lb injectors, stock fuel pump. Use some good 1.6 or 1.7 ratio roller rockers for extra punch. Use a King Cobra clutch, with stock iron or steel billet flywheel. MAF cars can use a 65 MM TB from the Explorer intake manifold and a 70MM MAF from a 94-95 Mustang. Drive train: 3:55 gears with soft tread compound tires. Use some Ford Racing unequal length headers, stock 2 1/4” cat pipe and some mufflers that don’t drone or get too much attention from the law enforcement or neighbors. The stock computer will handle all this with no problems and doesn’t need any help in 90% of the cases. No skinny or grossly undersize tires for the front: remember you still have to stop quickly in traffic. Make sure all the rubber bushings in the front and rear suspensions are in first class shape. Leave the emissions equipment intact and working. Removing or disabling it won’t get you any more HP or performance. Do not convert to carb or remove A/C: either one will reduce the resale value. Carb conversions cannot be titled for street use or get tags in some places. They definitely won’t pass smog inspections.
Street/strip: A little more slope to the torque curve with a gently sloping peak. Use slightly larger port volumes on intake and heads for more peak HP. Uses 3.55 or 3.73 gears to get the RPM’s up into a higher range quicker. Be prepared to sacrifice some low RPM throttle response in exchange for high RPM power. This by necessity will be a Mass Air or Mass Air conversion on 86-88 5.0 Mustangs, since stock speed density will not run well with the changes in engine airflow. Don’t get too crazy on any one engine part since you still have to drive the car on the street, and a mismatch can make street driving miserable.
Use stock or mild aftermarket cam, Ported GT 40, or 165-180 CC port volume aftermarket aluminum heads. Use a Trick Flow, Edelbrock Performer or equal intake manifold. Take a 73 MM aftermarket MAF calibrated for 24 lb injectors, and 24 lb injectors, 155 LPH fuel pump, Kirban adjustable fuel pressure regulator. Be prepared to shell out some $$$ for a custom burned chip using data gathered from a dyno run. Mass market chips will not get the job done. Use some Ford Racing unequal length headers, aftermarket 2 1/2” cat pipe and some mufflers that don’t drone or get too much attention from the law enforcement or neighbors. Drivetrain: expect the stock T5 to fail, so save your money for a super duty 5 speed trans. Tremec 3550, TKO 500 & TKO 600 are the best choices. Different gears in a stock T5 case work for some, but there is only so much power you can pass through a T5 in race mode before it breaks, even with stronger gears. Next are the Chassis mods: full length subframe connectors, different springs, different shocks, aftermarket lower and upper control arms with rubber or urethane bushings. Buy all the parts from someplace like Maximum Motorsports, Griggs or Steeda as a kit so that you know that all the parts fit and don’t argue with each other. Carry spare tires and wheels for the drag strip: skinnys for the front and drag radials for the rear. No skinnys for street driving! Over 85% of the breaking power is generated by the front tires, so skinnys won’t do the job in a panic stop situation. Disconnect the front anti-roll bar at the strip; reconnect it before you drive home. Leave the emissions equipment intact and working. Removing or disabling it won’t get you any more HP or performance. Do not convert to carb or remove A/C: either one will reduce the resale value. Carb conversions cannot be titled for street use or get tags in some places. They definitely won’t pass smog inspections.
Strip only: High RPM, High flow heads (185-215 CC port volume), wild cam, high flow intake manifold, 70 MM or larger TB, 80 MM or lager MAF, strip everything out of the car that doesn’t make it go faster. Carbs are OK if that’s what you want, but remember that as the temp/humidity/ barometric pressure/altitude changes, you have to re-jet and readjust the carb. EFI eliminates most of that with its built in compensation or you can tune of the fly with a high end Motes or Tweecer system combined with a wide band air/fuel ratio meter. Use custom headers, dumps and minimal mufflers. How fast you can go on 5 liters is a function of the skill level of the driver/mechanic and the size of your wallet.
TRAILER the car to the race track since it won’t be legal to drive it on the street. Drag slicks in the rear, skinnys up front, use 3.73 or bigger gears (4.xx) in the rear axle. Since you won’t be driving on long trips, the big gears with work with the high RPM power curve to get the best results. Drivetrain: TKO 500 & TKO 600 are the best choices. Different gears in a stock T5 case work for some, but there is only so much power you can pass through a T5 in race mode before it breaks, even with stronger gears. Next are the Chassis mods: full length subframe connectors, different springs, different shocks, aftermarket lower and upper control arms with rubber or urethane bushings. Buy all the parts from someplace like Maximum Motorsports, Griggs or Steeda as a kit so that you know that all the parts fit and don’t argue with each other. Remove the front sway bar, put an airbag in the rear spring of the side that spins the tire the most. Plan on a roll cage if you are truly serious about going fast: most strips will require it once you get to a certain ET range.
Autocross is a combination of Hot street engine and street strip chassis prep. The engine must accelerate quickly from low RPM and needs a broad, flat torque curve. Next are the Chassis mods: full length subframe connectors, different springs, different shocks, aftermarket lower and upper control arms with rubber or urethane bushings. Buy all the parts from someplace like Maximum Motorsports, Griggs or Steeda as a kit so that you know that all the parts fit and don’t argue with each other. Most of the time you’ll never hit third gear, so some 3.73 or bigger gears (4.xx) may help a lot. You’ll have to spend some more money on brakes since it kills brakes quickly. Rear disks, larger rotors up front, stainless steel brake lines, different brake pads. A 87-88 T Bird Turbo Coupe or SN 95 rear axle will be your best bet. Autocross will severely strain 1st & 2nd gears, so your T5 may take a premature dump. Save your money for a super duty 5 speed trans. Tremec 3550, TKO 500 & TKO 600 are the best choices.
All out road race is the most difficult of all: an engine that will run at high rpm hour after hour and never fail, yet pull hard out of the hairpin turns that will require a lot of torque at lower RPMs. In my opinion, guys that can successfully build a winning road race engine are the cream of the crop. Top this off with a chassis built for strip only duty, but with changes to the settings of springs, tires, roll bars brakes and shocks. It’s a whole other world of racing.
You’ll have to spend lots more money on brakes since it kills brakes quickly. Rear disks, larger rotors up front, stainless steel brake lines, different brake pads. Air ducting to cool the brake rotors will be a must. The brake rotors of cars on a high speed road course glow red after several hard laps of racing. Drivetrain: TKO 500 & TKO 600, and T56 close ratio are the best transmission choices.
Far too many people put a dab of this and a dollop of that, and then wonder why the car doesn't run worth beans. Then they think off the shelf computer chips will fix their mismatched parts problem. It won't You have to have a plan for what kind of performance you want: Hot street. Street/Strip, Pure strip, Autocross or Road course. Each one requires a different strategy and a different set of components.. Mismatch the components and you’ll have a car that falls flat on its face when you demand performance.
Everyone thinks HP! HP! HP! and thinks that peak HP is what they need. Peak HP is great for a drag strip car when it has the proper gears and tires to get the car up into the high RPM range where it develops that high peak HP near the finish line. On a street car, that strategy will have Honda Accords outrunning you, because you will never get the engine RPMs high enough without running over everything in your path.
Here’ the strategy: Always remember that there are some tradeoffs in any engine combination. Most of us don’t have enough money to “have it all” as if it was possible by some masterful combination of parts and tuning.
The following recommendations are for 5 Speed Manual transmission cars without NO2 or pressurized induction, stock short block.
1.) Hot street: Broad flat torque curve, high velocity airflow in the intake and heads for best throttle response. Gears suitable for reasonable gas mileage and long road trips without excessive engine RPMs. Stand on the gas pedal from a rolling start to squeeze into that gap in traffic in front of you, and it jumps quick and hard to get you there. Max RPM’s are 5200-5500 RPM for best power. Lopey cams may sound cool, but run poorly in a low RPM street environment.
Use stock cam, stock, GT40 or mildly ported stock heads, Cobra or Explorer/GT40 intake, advanced timing, stock 19 lb injectors, stock fuel pump. Use some good 1.6 or 1.7 ratio roller rockers for extra punch. Use a King Cobra clutch, with stock iron or steel billet flywheel. MAF cars can use a 65 MM TB from the Explorer intake manifold and a 70MM MAF from a 94-95 Mustang. Drive train: 3:55 gears with soft tread compound tires. Use some Ford Racing unequal length headers, stock 2 1/4” cat pipe and some mufflers that don’t drone or get too much attention from the law enforcement or neighbors. The stock computer will handle all this with no problems and doesn’t need any help in 90% of the cases. No skinny or grossly undersize tires for the front: remember you still have to stop quickly in traffic. Make sure all the rubber bushings in the front and rear suspensions are in first class shape. Leave the emissions equipment intact and working. Removing or disabling it won’t get you any more HP or performance. Do not convert to carb or remove A/C: either one will reduce the resale value. Carb conversions cannot be titled for street use or get tags in some places. They definitely won’t pass smog inspections.
Street/strip: A little more slope to the torque curve with a gently sloping peak. Use slightly larger port volumes on intake and heads for more peak HP. Uses 3.55 or 3.73 gears to get the RPM’s up into a higher range quicker. Be prepared to sacrifice some low RPM throttle response in exchange for high RPM power. This by necessity will be a Mass Air or Mass Air conversion on 86-88 5.0 Mustangs, since stock speed density will not run well with the changes in engine airflow. Don’t get too crazy on any one engine part since you still have to drive the car on the street, and a mismatch can make street driving miserable.
Use stock or mild aftermarket cam, Ported GT 40, or 165-180 CC port volume aftermarket aluminum heads. Use a Trick Flow, Edelbrock Performer or equal intake manifold. Take a 73 MM aftermarket MAF calibrated for 24 lb injectors, and 24 lb injectors, 155 LPH fuel pump, Kirban adjustable fuel pressure regulator. Be prepared to shell out some $$$ for a custom burned chip using data gathered from a dyno run. Mass market chips will not get the job done. Use some Ford Racing unequal length headers, aftermarket 2 1/2” cat pipe and some mufflers that don’t drone or get too much attention from the law enforcement or neighbors. Drivetrain: expect the stock T5 to fail, so save your money for a super duty 5 speed trans. Tremec 3550, TKO 500 & TKO 600 are the best choices. Different gears in a stock T5 case work for some, but there is only so much power you can pass through a T5 in race mode before it breaks, even with stronger gears. Next are the Chassis mods: full length subframe connectors, different springs, different shocks, aftermarket lower and upper control arms with rubber or urethane bushings. Buy all the parts from someplace like Maximum Motorsports, Griggs or Steeda as a kit so that you know that all the parts fit and don’t argue with each other. Carry spare tires and wheels for the drag strip: skinnys for the front and drag radials for the rear. No skinnys for street driving! Over 85% of the breaking power is generated by the front tires, so skinnys won’t do the job in a panic stop situation. Disconnect the front anti-roll bar at the strip; reconnect it before you drive home. Leave the emissions equipment intact and working. Removing or disabling it won’t get you any more HP or performance. Do not convert to carb or remove A/C: either one will reduce the resale value. Carb conversions cannot be titled for street use or get tags in some places. They definitely won’t pass smog inspections.
Strip only: High RPM, High flow heads (185-215 CC port volume), wild cam, high flow intake manifold, 70 MM or larger TB, 80 MM or lager MAF, strip everything out of the car that doesn’t make it go faster. Carbs are OK if that’s what you want, but remember that as the temp/humidity/ barometric pressure/altitude changes, you have to re-jet and readjust the carb. EFI eliminates most of that with its built in compensation or you can tune of the fly with a high end Motes or Tweecer system combined with a wide band air/fuel ratio meter. Use custom headers, dumps and minimal mufflers. How fast you can go on 5 liters is a function of the skill level of the driver/mechanic and the size of your wallet.
TRAILER the car to the race track since it won’t be legal to drive it on the street. Drag slicks in the rear, skinnys up front, use 3.73 or bigger gears (4.xx) in the rear axle. Since you won’t be driving on long trips, the big gears with work with the high RPM power curve to get the best results. Drivetrain: TKO 500 & TKO 600 are the best choices. Different gears in a stock T5 case work for some, but there is only so much power you can pass through a T5 in race mode before it breaks, even with stronger gears. Next are the Chassis mods: full length subframe connectors, different springs, different shocks, aftermarket lower and upper control arms with rubber or urethane bushings. Buy all the parts from someplace like Maximum Motorsports, Griggs or Steeda as a kit so that you know that all the parts fit and don’t argue with each other. Remove the front sway bar, put an airbag in the rear spring of the side that spins the tire the most. Plan on a roll cage if you are truly serious about going fast: most strips will require it once you get to a certain ET range.
Autocross is a combination of Hot street engine and street strip chassis prep. The engine must accelerate quickly from low RPM and needs a broad, flat torque curve. Next are the Chassis mods: full length subframe connectors, different springs, different shocks, aftermarket lower and upper control arms with rubber or urethane bushings. Buy all the parts from someplace like Maximum Motorsports, Griggs or Steeda as a kit so that you know that all the parts fit and don’t argue with each other. Most of the time you’ll never hit third gear, so some 3.73 or bigger gears (4.xx) may help a lot. You’ll have to spend some more money on brakes since it kills brakes quickly. Rear disks, larger rotors up front, stainless steel brake lines, different brake pads. A 87-88 T Bird Turbo Coupe or SN 95 rear axle will be your best bet. Autocross will severely strain 1st & 2nd gears, so your T5 may take a premature dump. Save your money for a super duty 5 speed trans. Tremec 3550, TKO 500 & TKO 600 are the best choices.
All out road race is the most difficult of all: an engine that will run at high rpm hour after hour and never fail, yet pull hard out of the hairpin turns that will require a lot of torque at lower RPMs. In my opinion, guys that can successfully build a winning road race engine are the cream of the crop. Top this off with a chassis built for strip only duty, but with changes to the settings of springs, tires, roll bars brakes and shocks. It’s a whole other world of racing.
You’ll have to spend lots more money on brakes since it kills brakes quickly. Rear disks, larger rotors up front, stainless steel brake lines, different brake pads. Air ducting to cool the brake rotors will be a must. The brake rotors of cars on a high speed road course glow red after several hard laps of racing. Drivetrain: TKO 500 & TKO 600, and T56 close ratio are the best transmission choices.
If it were me... I'd leave it in the box and store it out in the garage. One thing about this hobby... you can NEVER have too many spare parts laying around.
larrym1961
5 Year Member
Holds true for me also. I have a bunch of 5.0 parts in my storage unit. Probably should sell some of it.
Depends on what you've got in mind....
If you want a true bolt on, no hassle set up, that retains all of your stock emissions hardware, stock with a '96 to early-'97 Explorer top end. They still utilize the original 3-bar GT40 heads and the intake is drilled for the internal EGR design like your Mustang is.
If you go with the late-'97 and up GT40 parts, you'll get the slightly more desirable "P" castings, but you may have issues with exhaust header fitment because of the spark plug location. Also the later intakes don't have the internal EGT set up like the earlier ones do and you'll need to forego your EGR system altogether.
Both are good set ups and will work, it just depends on what you’re willing to sacrifice to make one work over the other. If it were me, I’d stick with the early head, bolt it on and go.
You’re not going to set the world on fire with the GT40 stuff, but it’ll give you an honest 35-45hp boost in performance over your current ET7E hardware and in a nice, broad street friendly power band to to boot.
The setup I had in my fox was an explorer engine with the standard 3 bar gt40 heads and explorer intake. I swapped in a tfs1 cam, upgraded valve springs, 65mm tb, shorty headers, magnaflow catted x, and flowmeter catback.
Untuned I was at right about 240 to the wheels on a very hot day. untuned and without traction, spinning through 1st and 2nd, I was doing 8.7 in the 1/8th which is right around mid 13s. I have friends with similar combos running high 12s. Very stout combo for basically a bunch of junk yard crap. This exact engine will be going into my 94 gt very soon.
Untuned I was at right about 240 to the wheels on a very hot day. untuned and without traction, spinning through 1st and 2nd, I was doing 8.7 in the 1/8th which is right around mid 13s. I have friends with similar combos running high 12s. Very stout combo for basically a bunch of junk yard crap. This exact engine will be going into my 94 gt very soon.
Cool yeah i woud like to just bolt it on and go honestly lol but thanks for the info gearbanger101 i am sure i will have more questions for you down the road lol but for now got my list started.
LOL. man this made me chuckle a bit. I think you have the whole modification thing a bit backward. Start with your goals and work from there. If you're trying to build something on a small budget, then stick with the stock 302. If you're running a 302, stick with a 165-185cc intake head, and then get a supporting intake for those heads. Long-runner intakes are preferred on the street, especially on low end builds, which usually are running stock heads, or GT40 heads. These heads don't have the flow to high rpm. So, you optimize power in the midrange. This is achieved best with a GT40/explorer/cobra/performer intake. With these intakes and a little port matching a 70mm throttle body is the perfect fit.
If you buy an intake to fit the throttle body, you'll likely end up with a high RPM range intake like the Track heat, Systemax, or RPM series intakes that will cost you low end torque. They will try to make more power up high where you'll be restricted by your heads' ability to flow. The result is a lack of both low-end/mid-range torque and high rpm power. What the guys here are trying to explain is that since you're running stock heads and you're likely to stay with a 302 for while, you're best off running one of the intakes mentioned and a corresponding 65-70mm TB.
Good luck!
Oh, and I think 12s are pretty easy. click here for bob cosby's 12 second recipe.
The basic stuff should be enough to get you there:
Basic tune up if needed (plugs, fuel filter, cap & rotor, wires). Then add the following: 1 5/8" long tube headers, Cobra intake, 65-70mm TB, 70-80mm MAF (calibrated for your injectors - I would go straight to 42lbs injectors and a Walbro 255 LPH or one of those new 340LPH pumps I've been hearing about to give yourself more room for future growth), underdrive pullies (not on alternator), K&N filter, air silencer removed, 3.73 gears, Drag radials, disconnect/removed sway bar, 50/50 shocks up front, 90/10s in the rear, airbag on passenger rear, good shifter for a manual or a shift kit in an AOD, remove the dog-bone from rear differential and the spare tire and jack from the back of the car, bump the timing to 14*, and while you're at it add subframe connectors.
Now, you can get there without all of the stuff in red and save a few bucks while you're at it, but that stuff is all a really good idea, and will make your car a consistent 12 second performer. Heads are not necessary to get solidly into the 12s, but they are the next logical component following the list above, and will make a HUGE difference if you spring for a premium set. With just adding heads and a cam to the above list, you can literally knock off another second in your ET and add another 8-10 mph to your traps. If you think you'll go this route, plan the parts you buy from the beginning around the finished combo. i.e. maybe wait to buy a Performer RPM, or systemax series intake instead of a performer or GT40 series intake knowing you're sacrificing a bit now to optimize the end-result.
The basic stuff should be enough to get you there:
Basic tune up if needed (plugs, fuel filter, cap & rotor, wires). Then add the following: 1 5/8" long tube headers, Cobra intake, 65-70mm TB, 70-80mm MAF (calibrated for your injectors - I would go straight to 42lbs injectors and a Walbro 255 LPH or one of those new 340LPH pumps I've been hearing about to give yourself more room for future growth), underdrive pullies (not on alternator), K&N filter, air silencer removed, 3.73 gears, Drag radials, disconnect/removed sway bar, 50/50 shocks up front, 90/10s in the rear, airbag on passenger rear, good shifter for a manual or a shift kit in an AOD, remove the dog-bone from rear differential and the spare tire and jack from the back of the car, bump the timing to 14*, and while you're at it add subframe connectors.
Now, you can get there without all of the stuff in red and save a few bucks while you're at it, but that stuff is all a really good idea, and will make your car a consistent 12 second performer. Heads are not necessary to get solidly into the 12s, but they are the next logical component following the list above, and will make a HUGE difference if you spring for a premium set. With just adding heads and a cam to the above list, you can literally knock off another second in your ET and add another 8-10 mph to your traps. If you think you'll go this route, plan the parts you buy from the beginning around the finished combo. i.e. maybe wait to buy a Performer RPM, or systemax series intake instead of a performer or GT40 series intake knowing you're sacrificing a bit now to optimize the end-result.
If you've already got the 75mm TB, I would just keep it and run it. An Explorer/GT40 type intake opening is very close to 70mm from the factory- like 68mm. A couple minutes with a Dremel and you'd be at 75mm.
It's not like there is a huge difference in drivability between a 70 and a 75. In fact, I bet the difference is negligible, if there is any at all. If there are guys successfully running 90mm TBs on street driven 302s (and there are), then a 75mm TB isn't going to be a deal breaker for you. If anything, it will leave room to grow into bigger and better combos in the future, and these guys know I am a huge proponent of "leaving room to grow".
I wouldn't wish a 65mm TB on my enemies. What a huge waste of money. Unless it fell in your lap, I would not spend money on a 65. I ran a 70mm TB on a stock intake for years (port matched). If you can fit a 70mm TB on a stock intake, with good drivability (I had many thousands of street miles on that), why go smaller?
It's not like there is a huge difference in drivability between a 70 and a 75. In fact, I bet the difference is negligible, if there is any at all. If there are guys successfully running 90mm TBs on street driven 302s (and there are), then a 75mm TB isn't going to be a deal breaker for you. If anything, it will leave room to grow into bigger and better combos in the future, and these guys know I am a huge proponent of "leaving room to grow".
I wouldn't wish a 65mm TB on my enemies. What a huge waste of money. Unless it fell in your lap, I would not spend money on a 65. I ran a 70mm TB on a stock intake for years (port matched). If you can fit a 70mm TB on a stock intake, with good drivability (I had many thousands of street miles on that), why go smaller?
Can you open a stock take up to 75mm? If not, it's a bad idea.
If so, it's going to neck down somewhere. I'd predict a very slight gain in going from a 65mm TB to a 70 on a GT40 intake. I predict almost no power increase going from a 70 to 75. On a stock or GT40 intake, I think you might even hurt performance. just a guess...
I made 320 with a 65mmTB on a Cobra intake with ported lower/AFR 165s/FTI custom cam. How much more would I have made with a 70? Maybe a few ponies. A
If so, it's going to neck down somewhere. I'd predict a very slight gain in going from a 65mm TB to a 70 on a GT40 intake. I predict almost no power increase going from a 70 to 75. On a stock or GT40 intake, I think you might even hurt performance. just a guess...
I made 320 with a 65mmTB on a Cobra intake with ported lower/AFR 165s/FTI custom cam. How much more would I have made with a 70? Maybe a few ponies. A
Can you open a stock HO intake to 75mm? I dunno. I thought he was going with a GT40 style intake...?
Anyway, I can't argue with you about there being a very small gain between a 65 and a 70 or a 70 and a 75. The difference is so minute, it's almost comical that some people sweat it out so much. IMO, there should be 3 TB sizes on the market- 70, 80 and 90. My argument is just that pretty much any intake can accommodate a 70, and since there is no real downside to running a 70 over a 65, why run the 65 at all? I think the only reason the 65 exists is because that's what Ford put on the '93 Cobra, and when FRPP put it on the market, companies like BBK followed suit.
Eh, it's a moot point. If he's already got the 75, I say run it. Just make sure the manifold is port matched, and everything will be hunky dory.
Not safely. At 75mm, it doesn't leave a lot of room for gasket sealing surface on a stocker. And I would think the amount of bottle neck left afterwards would be more of a hinderance with all of that air smashing into it afte the big 75mm opening.
The differences is less extreme with the Cobra/GT40/Explorer intakes, but I really can't see anything larger than a 70mm on one of those being of any use. The intakes just don't flow anymore air than that anyway.
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