thoughts on a 347 with GT40P heads and GT40 intake.

[MarSaleenMustan]

As the title says, what are your thoughts on this setup?, I would like to do this to my '88 Notchback by the end of the '05 year. My plan is to put in a 347 forged stroker from either CHP or DSS (most likely put it togeather my self, but just have a shop bore/prep the block.) and top it off with some used GT40P heads and the same intake. The reason i have this set up is for cost issues, i figure for the 347 stroker kit its 1k, used heads/intake(if i get lucky i may find one with them ported) around $600 more or less, 500 or so for machining the block, and around 300 for miscelaneous things. And this can be done for around 2500 which is a reasonable budget, of course this isnt going to be a street terror in it self, but since its going into my '88 LX 5spd Notchback with AC delete(and other weight savings) and the following a pro 5.0 shifter, mac pro chamber/mufflers with alum pulleys and 3:73 gears I figure this should put me well into the 12s with DRs, maybe 11s with tuning and practice. its also got the eibach pro launch springs with airbag and HPM Jr. lowers.
Now I havent done too much reasearch on the difference between GT40 anad GT40P heads, but I feel that for my budget build up they should be good enough if i find the right ones(aka already ported) if anyone could enlighten me on the difference i would appreciate it. If budget allows I may go with a set of aluminum GT40s for weight savings. Basically my goal with this car is to get it into the 11s with a no more than 3k budget on motor alone and then be able to do a SC a year or two later and do 10s. I know i'd have to upgrade my tranny, but the T5 should hold up as long as I dont dump it at high rpms off the line or powershift all the time. by the way this wont be my daily driver, thats my '95 GT's duty. sorry for the long post but your opinions/comments would be greatly appreciated.

 

[281pony]

what about maf/tb/exhaust/rockers/cam/ect?

gt40p's are ok heads, but can benefit alot from porting from what i understand. you will need special headers IF you go with the gt40 p's. the cast and aluminum gt40's will be fine with stock type headers. i would save up some more money and get a little better intake with that.

that 300 estimate will come short also. new lifters 100, oil/filter (should get two times worth for early break-in mile changes) $30, spark plugs $8, complete gasket kit $100, headbolts $40, oil pump/shaft possibly, injectors/maf $300-600, on and on. specific upper/lower intake gaskets for gt40 intake.

what about your clutch? engine mounts? see where im going? even assembling the shortblock yourself, 2500 dollars for building a complete stroker longblock is not enough i dont think. getting a set of gt40 heads/intake for 600 together is going to be kind of tough also, and they wont be ported. shipping will be expensive also. just a bunch of things that come to mind since i just built my motor from scratch almost.

 

[Jkstang78]

"Basically my goal with this car is to get it into the 11s with a no more than 3k budget on motor alone and then be able to do a SC a year or two later and do 10s."

I think it would be a waste of your time and you will not be happy with the results. Change the heads and intake. Head I would go with the edelbrock Jr or Afr 185 or 205. Intake edelbrock rpm II. I say go striaght for the supercharger.

 

[MarSaleenMustan]

what about maf/tb/exhaust/rockers/cam/ect?

gt40p's are ok heads, but can benefit alot from porting from what i understand. you will need special headers IF you go with the gt40 p's. the cast and aluminum gt40's will be fine with stock type headers. i would save up some more money and get a little better intake with that.

that 300 estimate will come short also. new lifters 100, oil/filter (should get two times worth for early break-in mile changes) $30, spark plugs $8, complete gasket kit $100, headbolts $40, oil pump/shaft possibly, injectors/maf $300-600, on and on. specific upper/lower intake gaskets for gt40 intake.

what about your clutch? engine mounts? see where im going? even assembling the shortblock yourself, 2500 dollars for building a complete stroker longblock is not enough i dont think. getting a set of gt40 heads/intake for 600 together is going to be kind of tough also, and they wont be ported. shipping will be expensive also. just a bunch of things that come to mind since i just built my motor from scratch almost.

Yeah after i posted it i thought about all of the micelaneous pieces, afterall the engine has 166K miles on it now, I did say 3k afterwards, I work at Autozone so i'd get a discount on head gasket set/bolts, oil pump, and other small parts. as far as headers i'm running the stock ones all i've got is the prochamber and mac mufflers/tips. I've seen some ported Cobra/GT40 intakes for around 400 or so ported. As far as injectors/mafs... i'm gonna have to hunt for a good deal. i think it can be done with some luck and used parts.

 

[MarSaleenMustan]

"Basically my goal with this car is to get it into the 11s with a no more than 3k budget on motor alone and then be able to do a SC a year or two later and do 10s."

I think it would be a waste of your time and you will not be happy with the results. Change the heads and intake. Head I would go with the edelbrock Jr or Afr 185 or 205. Intake edelbrock rpm II. I say go striaght for the supercharger.

I mean correct me if i'm wrong, but i think a 331 with those ported heads/intake and corresponding injectors/maf with the exhaust i've got and pulleys with K&N and Ford Racing wires can do 300-320rwhp or so, not to mentino this is going into an LX 5spd notchback wich i've removed some things off of it to lighten it up. all these plus DR's should i think give me low 12s. As far as AFRs, yeah if i had that kind of money i'd get 185s, and a "better" intake, but then you're talking about 1,500 or so for that, where as like i stated above with some luck i could probably find both heads and intake for around 600-800 bucks.(trust me, i've searched and i came up with someone selling both heads and intake for 500) As far as going straight for the Sc, i would also, but considering the 166K miles on the engine(not aware if its been rebuilt or not, runs strong, but just dont know) I dont wanna risk it and blow something up, I'd rather rebuild the stock block with the parts mentioned above.

 

[Jkstang78]

Ok I know your on a budget but is that all you want to make is 300-320rwhp. You going to want to go faster after you get board with it. We all do. Right now I am in the process of building a 331 myself. Just in parts a lone I have $5000 and still no short block. I should have gone to the superchager instead of building this motor. I would have been done already and at my goal already with is 400 to the wheels. So I am hoping to have a killer engine here.

New D.S.S level 20 block,Scat 4340 Crankshaft "standard style,3.250 stroke/1.680pin,Scat H-Beam Rod 5.400 rod length/.912 wrist pin,SRP Forged Piston flat top/.912 pin dia,11 to 1 compression,ARP Rod Bolts,Crankshaft was externaly balanced,Clevite race bearings, rod, and main bearings,Speed pro Piston rings,Edelbrok RPM II Intake,Edelbrock Victor Jr. Heads, Accufab 75mm T.B., Vortec Fuel Pressere Rails, & 42 lbs injectors,AFM Power Pipe & 75 mm mass air meter.

 

[BlackDrop50]

WHY BOTHER

 

[BlackDrop50]

Waste of money, you are stretching your budget too thin, you will not finish it, you will be dissapointed


Would be smarter to go with heads cam intake on stock shortblock. If you don't listen to me, don't get mad at yourself later.

 

[MarSaleenMustan]

Ok I know your on a budget but is that all you want to make is 300-320rwhp. You going to want to go faster after you get board with it. We all do. Right now I am in the process of building a 331 myself. Just in parts a lone I have $5000 and still no short block. I should have gone to the superchager instead of building this motor. I would have been done already and at my goal already with is 400 to the wheels. So I am hoping to have a killer engine here.

New D.S.S level 20 block,Scat 4340 Crankshaft "standard style,3.250 stroke/1.680pin,Scat H-Beam Rod 5.400 rod length/.912 wrist pin,SRP Forged Piston flat top/.912 pin dia,11 to 1 compression,ARP Rod Bolts,Crankshaft was externaly balanced,Clevite race bearings, rod, and main bearings,Speed pro Piston rings,Edelbrok RPM II Intake,Edelbrock Victor Jr. Heads, Accufab 75mm T.B., Vortec Fuel Pressere Rails, & 42 lbs injectors,AFM Power Pipe & 75 mm mass air meter.

Trust me, I would want more, a lot more.... lets put it this way, The engine i wanna build would be "capable" of 700rwhp+, it would be a 351 based 427 SC'd powerplant with AFR 205s and an a nice intake, with forged internals/ balanced crank and blueprinted FRPP aluminum 351 block, but of course this is way out of my league at this point in time from a financial view. Thats why i'm going with this particular setup for now. As far as "only" 300 hp, yeah, that would be the NA set up, but i plan on getting 8:1 compression pistions from the get go for the SC i'd put on the 347 a year or two down the line(after next year of course) that "complete" set up would yield me around 450rwhp on a conservative tune reason being the stock factory block's limitations, there'd be no point in investing(i think) on AFR 185s and an RPMII intake if they cannot be taken full advantage of given the block's limitations. Thats why ultimately i think the ported GT40P's and ported GT40/Cobra intake along with the SC at 10psi should give me the power reliably. but for now 300HP on a fresh(read fresh/rebuilt) 347 engine would be "enough" to get me into the 12s untill i get the SC, then its 10s

I did notice that you have an 11:1 compression on your current setup, i dont think those piston tops will like boost at all, not on pump gas anyway. sounds like you've got a good setup your self, should get 400rwhp or so from your na setup, but then again, i'm assuming you're using a ford factory(though prepped for level 20) block, i wouldnt go over 500rwhp unless i had to race someone for pinks

 

[MarSaleenMustan]

Waste of money, you are stretching your budget too thin, you will not finish it, you will be dissapointed


Would be smarter to go with heads cam intake on stock shortblock. If you don't listen to me, don't get mad at yourself later.

Thanks for the heads up, I can see how you spent lots of money with your engine, custom camshaft, AFRs, edelbrock intake... and who knows what else. I maynot be explaining my self as well as i think ishould, but basically I'm not looking to build anything that will make 500+hp(for i feel its a waste of money to dump that much onto a stock block) with flow numbers out of this world, thats why i've chosen to go with that "not so great" heads/intake combo. Biggest reason why i dont just put heads cam and intake is because the block already has 166K miles on it, I would rather freshen it up now even if it means not having the best flowing stuff. for the price of top of the line H/C/I I could have a fresh 347 short block, of course i'm gonna have enough saved for at least the heads/intake/gaskets part of the deal that way i can do that while the engine is out of the car.

 

[MarSaleenMustan]

anyone else?

 

[BlackDrop50]

Trick flow twisted wedges can be used as an early head then port them out later, along with a track heat intake and some trickflow cam. Only $2,000 for the whole top end kit.

No point in choking the 347 when you could (re)build a simple 306 that would smoke it, then throw on a supercharger on top of it. No need to go with a 347. Trust me. Large oil consumption and low mileage motor life = not a daily driver or boost friendly, unless you wanna spend $$$. Do it right the first time instead of kicking yourself in the ass.

 

[MarSaleenMustan]

Trick flow twisted wedges can be used as an early head then port them out later, along with a track heat intake and some trickflow cam. Only $2,000 for the whole top end kit.

No point in choking the 347 when you could (re)build a simple 306 that would smoke it, then throw on a supercharger on top of it. No need to go with a 347. Trust me. Large oil consumption and low mileage motor life = not a daily driver or boost friendly, unless you wanna spend $$$. Do it right the first time instead of kicking yourself in the ass.

Do you really think ported GT40P's and ported GT40 intake would be THAT much of a bottle neck?, from the flow numbers i've seen they arent all that bad. I dont see how a 306 with "similar flowing heads" aka unported trick flows vs ported GT40s would smoke the 347 As far as the low motor life, from what i've read oil consumption was an issue in the early days of the 347 stroker, but has been improved since. not a boost friendly set up?... i dont know how you came to that conclusion either Also as I mentioned above its not going to be a daily driver, that will be my '95 GT's duty. the Notch would only be a Friday/Saturday night cruiser, drag racer. Not a daily driver by any means.

 

[BlackDrop50]

mine consumes a lot of oil

stock block = breakage

 

[MarSaleenMustan]

mine consumes a lot of oil

stock block = breakage

That is why i feel I dont "need" the best heads with this combo, because of the stock block's limitations, as i mentioned above i think it'd be a waste of money to spend tons of money on it and not be able to take full advantage of the internals/heads/intake. Like i said i'm not looking for anymore than 450rwhp with this block. anything more than that and i'm asking for trouble, thats why i feel that the heads and intake i have selected are enough to support that power, at least the 300 or so from the na stroker alone.

 

[Grn92LX]

mine consumes a lot of oil

stock block = breakage

Don't blame the cubic inches, blame the builder or machine work or possibly you bought junk rotating assembly? 3.40 stoke cars DO NOT BURN OIL!!! Its ALL in the machine work/build/good name brand parts


MarSaleenMustan, don't waste your money putting that forged stuff in your car. ALL you need is a good name brand cast steet rotating assembly like an eagle or a scat 9000 kit. If your set on the P heads by all means use them. I would suggest a better intake over the GT40 though. Something mild (but way better than a GT40) like an edelbrock RPM. Either way with those heads you will NEED to replace the valve springs, seals and check them for straightness. I'd have them clean up milled at least. Talk to Ed curtis or jay allen for a cam even though your combo is mild. You can always put better heads down the road, but by doing the 347 shortblock you have build your foundation that can be improved down the road.

 

[MarSaleenMustan]

Don't blame the cubic inches, blame the builder or machine work or possibly you bought junk rotating assembly? 3.40 stoke cars DO NOT BURN OIL!!! Its ALL in the machine work/build/good name brand parts


MarSaleenMustan, don't waste your money putting that forged stuff in your car. ALL you need is a good name brand cast steet rotating assembly like an eagle or a scat 9000 kit. If your set on the P heads by all means use them. I would suggest a better intake over the GT40 though. Something mild (but way better than a GT40) like an edelbrock RPM. Either way with those heads you will NEED to replace the valve springs, seals and check them for straightness. I'd have them clean up milled at least. Talk to Ed curtis or jay allen for a cam even though your combo is mild. You can always put better heads down the road, but by doing the 347 shortblock you have build your foundation that can be improved down the road.

Thanks for your insightful input. as far as the rotating assembly it self, i'm gonna go with forged rods/pistons and a cast crank due to both cost but most importantly because there is no need to get a forged one in that first of all it weighs more, and second i think it would be a waste on a stock factory block. correct me if i'm wrong please. As far as the heads, yeah I thought about it and i'd put in some better springs/ and stainless steel valves with good retainers. I know that adds a bit more to the overall cost, but it shouldnt be THAT much. as far as a cam it would defenetly need to be a smog legal one. CA buerocrats(sp?) suck when it comes to this.
no ones told me this here, but would the ported GT40 heads be good enough to make 300 or so HP on this motor? I know you suggested going with a better intake, but would a ported lower again be enough for this? Basically this isnt my "dream engine" by anymeans, but i want to build something relatively inexpensive that isnt going to be a daily driver either but will put some pretty good 1/4 mile numbers(12s, maybe 11s with an SC down the road)
years down the road I will build a DART block based 408-427, but for now this will suffice given the financial situation.

 

[Grn92LX]

You are 100% correct on the forged crankshaft being way overkill. Thats why I suggested the regular scat 9000 kit or the eagle kit. Honestly, once you start adding in the price for the heads + money needed to be put into them your better off buying a set of trickflow track heats or afr 185's. These heads out of the box are mild for a good 347 but like you said its not your dream engine. Basically for not too much more money you can still stay mild and do 375rwhp. But if a low 300 is in fact your goal, neither head is required. Just buy a used set of P heads change the springs, seals and have them clean up milled (about $200 for all this) use the RPM intake definatly over the expensive gt40. I really dont know what to say about an emissions legel cam since you need a carb sticker. Do you have any "hook ups" when it comes to inspections? That means you have to run shortys and cats, god thats gay for a 347 I'm not aware of many carb legal cams besides the E303. Lots of cams will pass but they dont have a carb sticker.

 

[MarSaleenMustan]

You are 100% correct on the forged crankshaft being way overkill. Thats why I suggested the regular scat 9000 kit or the eagle kit. Honestly, once you start adding in the price for the heads + money needed to be put into them your better off buying a set of trickflow track heats or afr 185's. These heads out of the box are mild for a good 347 but like you said its not your dream engine. Basically for not too much more money you can still stay mild and do 375rwhp. But if a low 300 is in fact your goal, neither head is required. Just buy a used set of P heads change the springs, seals and have them clean up milled (about $200 for all this) use the RPM intake definatly over the expensive gt40. I really dont know what to say about an emissions legel cam since you need a carb sticker. Do you have any "hook ups" when it comes to inspections? That means you have to run shortys and cats, god thats gay for a 347 I'm not aware of many carb legal cams besides the E303. Lots of cams will pass but they dont have a carb sticker.

300rwhp is my goal with the NA setup, 400 would be with the SC. as far as "expensive" GT40 intake, i've seen some for as low as 150 both upper and lower. but i do see your point in spending an extra 200 or so and get an RPM unit or something alike. Whats the main difference between the Cobra intake and the GT40 one? i'm talking about the tubed one.

 

[Grn92LX]

The main difference really is the looks. The GT40 upper 'might' flow a little better than the cobra upper but nothing you'll notice. The RPM would be a good choice for your goals. You'll do over 400 with a s/c fyi.