Budget torquier 4.6?

Not a Mustang technically, but it is a 2V 4.6/TR6350 powered car.

I have been driving my TR3650 swapped Marquis around for a few months now, and I enjoy it a lot. The only complaint I have is that even with my 3.55 rear axle, the car still feels a little weak up until around 3K. I’ve been thinking lately about putting together a lighter 4.6 2V with a powerband that is lower down in the rpm range than stock, ideally with improvements across the 1500-4500 rpm in torque especially. I want to do so on a sub grand budget as well. Here’s my thoughts, I’d appreciate feedback.

Parts I already have on hand or in car:
-Dragon oval plenum
-twin 60mm throttle body from a GT500
-80mm MAF and air intake
-28lb EV14 injectors
-109k PI engine (would prefer not to open just in case)

Parts I have access to for cheap:
-Typhoon intake manifold
-Kooks headers
-2.5” exhaust

Parts under consideration for the “new” motor:
-NPI rotating assembly
-Explorer block
-DIY ported PI heads
-NPI cams and valve springs

From my understanding talking to a few others, the higher duration and reduced valve overlap of the NPI cams should shift my peak torque down about a grand in rpm’s to peak at 3500 rpm, while the NPI/PI bastardization should give me a point and a half more compression than stock for 10.5:1ish compression ratio. Using the dragon plenum and dual bladed GT500 throttle body should improve throttle response, and porting the heads and maybe intake if I use the typhoon one should allow the motor to make use of the extra flow from the throttle body. Headers should help the motor breath across the board. What’s the vibe, am I on the wrong rabbit trail or should this end up being a budget torquier 4.6 2V? Any places I could make improvements and stay in budget?
 
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Not a Mustang technically, but it is a 2V 4.6/TR6350 powered car.

I have been driving my TR3650 swapped Marquis around for a few months now, and I enjoy it a lot. The only complaint I have is that even with my 3.55 rear axle, the car still feels a little weak up until around 3K. I’ve been thinking lately about putting together a lighter 4.6 2V with a powerband that is lower down in the rpm range than stock, ideally with improvements across the 1500-4500 rpm in torque especially. I want to do so on a sub grand budget as well. Here’s my thoughts, I’d appreciate feedback.

Parts I already have on hand or in car:
-Dragon oval plenum
-twin 60mm throttle body from a GT500
-80mm MAF and air intake
-28lb EV14 injectors
-109k PI engine (would prefer not to open just in case)

Parts I have access to for cheap:
-Typhoon intake manifold
-Kooks headers
-2.5” exhaust

Parts under consideration for the “new” motor:
-NPI rotating assembly
-Explorer block
-DIY ported PI heads
-NPI cams and valve springs

From my understanding talking to a few others, the higher duration and reduced valve overlap of the NPI cams should shift my peak torque down about a grand in rpm’s to peak at 3500 rpm, while the NPI/PI bastardization should give me a point and a half more compression than stock for 10.5:1ish compression ratio. Using the dragon plenum and dual bladed GT500 throttle body should improve throttle response, and porting the heads and maybe intake if I use the typhoon one should allow the motor to make use of the extra flow from the throttle body. Headers should help the motor breath across the board. What’s the vibe, am I on the wrong rabbit trail or should this end up being a budget torquier 4.6 2V? Any places I could make improvements and stay in budget?

Maybe look into a 5.4. Or even an aluminum flywheel.

Otherwise I’d go ported NPI heads(round ports better for low rpm flow), PI intake(typhoon sucks), PI or custom cams, long tubes, 4v pistons, tune.

Let me know if you ever want to sell the oval plenum. I don’t think it or the TB and maf will make a difference.
 
Got talked into seeing what exhaust and cams will do before bumping compression. Got some kooks in the mail and I’m going to pick up some comp XE262AH cams and beehive springs with 100 miles on them for $350 tomorrow. Might have a friend port me a set of PI heads as well since I’ll probably do headers and cams out of car, but we will see
 
Like I said, all of this about adds up to the cost having gears swapped for me. Decided against porting heads, but the cams and valve springs were cheap, headers were used and also dummy cheap for vic parts, Ill be sitting nice and pretty around the $700 mark once I buy gaskets and the pipe to do a 2.5” header back.
 
I've had two CVs. The first had a 3.55 rear gear and the second a 2.73. The 3.55 was much different in town and off the lights than the other car. The advice to go with a gear change is well founded and would make the single biggest difference in the car---without engine mods that may make it more finicky. The other observation I'll make from experience is the CVs use up a lot of torque/power just getting the power to the ground---long wheelbase, relatively soft suspension/bushings, long driveshaft, body twist, etc, in a relatively heavy package. I get your desire to make this Panther a performer, but for my money a blower and a rear gear set would be the way to go. I think you'll hit the "no pay back" point in a NA 4.6 build (like so many others have noted in threads too numerous to count) pretty quickly (if not already) in that chassis, especially since so many NA mods tend to raise the optimum operating rpm vice lower it. That said, do what you want.
 
Before you do anything, see if you can find a used blower. Twin screw or roots style. Bottom end torque for days with bolt on simplicity.
Wayyy outside what I want to spend, plus weight. Based on how much of a difference my CAI setup made over the P71 box people usually use, as well as the 2x60mm GT500 throttle body and ported/polished Dragon plenum, as well as how small of a difference they should in theory make relative to long tubes, a 2.5” exhaust, and XE262AH cams, I would say I’ll probably be satiated for a while once I get what I have together on the car.
 
I've had two CVs. The first had a 3.55 rear gear and the second a 2.73. The 3.55 was much different in town and off the lights than the other car. The advice to go with a gear change is well founded and would make the single biggest difference in the car---without engine mods that may make it more finicky. The other observation I'll make from experience is the CVs use up a lot of torque/power just getting the power to the ground---long wheelbase, relatively soft suspension/bushings, long driveshaft, body twist, etc, in a relatively heavy package. I get your desire to make this Panther a performer, but for my money a blower and a rear gear set would be the way to go. I think you'll hit the "no pay back" point in a NA 4.6 build (like so many others have noted in threads too numerous to count) pretty quickly (if not already) in that chassis, especially since so many NA mods tend to raise the optimum operating rpm vice lower it. That said, do what you want.
Oh I know lol, I’m already well past the point of no return. I probably have $14k into the car just in what’s on it between what I paid for it, the 5 speed swap, 3.55 LSD rear end, billet control arms and watts link, sway bars, aluminum hood, 14” brakes, and other stupid :poo: I’ve done trying to make it handle well and be fun to drive.
 
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Either do a better gear, or save, and do a blower. A better gear swap is probably the cheapest bang for the buck. I have 4.10’s , and could not imagine having anything under it for gear ratio! If anything, and mine being cammed, I have tossed the idea of going 4.30’s for years myself lol!
 
Stock NPI cams are not worth even considering. They are far to low in lift to support any real power. A stock pi cam in a npi head will pick up 10-15ft/lbs across the whole powerband even with the crappy stock NPI manifold still equipped. Stock Pi cams and induction beat out a lot of bigger cammed combos up to around 4500 so unless you are hitting redline every shift, stock pi stuff is probably going to be your best bet. Id say have 4.10s and 26 inch tall tires installed and torque wont be an issue for a while.