I've owned 2 4th gens, both 96's and they were nice and all, but I love the stlying of my 86 Trans Am. But there are also things of the 4th gens that I liked, the dash and drivetrain for instance.
If you look at my sig, my car is basically a 4th gen in a 3rd gen body.

 

13.88@97mph with stock heads, stock intake, stock runners, stock exhaust manifolds, cheap paper air filters, street tread... the TPI cars induction isnt as bad as everyone thinks, went 12.88 with a 100 shot of n2o, still working out some problems with the 150 and 175 n2o pills and planning on installing my headers tomorrow - I have 392ft lbs of rear wheel torque and 518 torque with nitrous, n around 225 rwhp n/a and 303hp on n2o. TPI's are torque monsters, if you wanna do some ECM programming, put in a nice cam, high stall and a Holley Stealth ram, you'd see low 12's naturally aspirated without a problem, those HSR's will pull to 6200rpm easy.

Engine:
- Factory 350 roller block bored .030 over (355c.i.)
- Flat Top (aprox 10:1) Pistons
- Moly Piston Rings
- Remanufactured Stock Rods
- 10/10 Crank
- Stock Camshaft
- 1.6 Roller Rockers
- 15,000 miles since valve job

Bolt On's:
- Crane Adjustable Fuel Pressure Regulator
- Throttle Body Airfoil (Hypertech?)
- Home made Ram Air using A/C Duct
- March Performance Under drive Pulleys (Crank & Alternator)
- Removed All Emissions Equipment

Transmission & Rear End:
- Dacco Detroit 2300-2500 Stall Torque Converter (footbrake's 2400)
- Rebuilt 700R4 with Superior Shift Kit
- 3.23 Rear Gears/Stock Posi

Suspension:
- Polyurethane Sway Bar End Links (remove sway bar at track)
- Polyurethane Sway Bar Bushings
- Polyurethane Motor Mounts
- Polyurethane Transmission Mount
- Polyurethane Torque Arm Mount
- Lakewood Rear Lower Control Arms
- Eibach Pro-Kit Lowering Springs

Exhaust:
- 3" Exhaust Cut Out in place of Catalytic Converter
- Stock Exhaust Manifolds

Wheels & Tires:
- Dunlop SP5000 255/50R16's on the back 16x8" IROC Rims, 30psi on the track
- Dunlop SP5000 245/50R16's on the front 16x8" IROC Rims, 42psi on the track

 

To zepher because of his girls

 

Thanks Zepher and Nitromethane, those are the kind of answers I was in search of when I posted this topic. Nitromethane, have you tried the HSR on your engine, just for comparison sake?

 

Not personally, but a friend of mine is gonna put one on his 86 t/a with ZZ4 cam in about 1-2 months, he has it sitting on his work bench, it'll definately be a major improvement over stock TPI, that thing is basically a modified tunnel ram. I can't remember exact dyno numbers but there was a kid at Vinci HiPerformance on the dyno with a HSR who peaked at 6200rpm, not sure what kinda cam, but i believe he was running low 12's naturally aspirated, possibly high 11's. I'm tempted to get one some day but I've got a back half project to pay for, when it run's 9's I'll start playing with my IROC some more - Headers are going on this tuesday, there's a dyno day coming up on the 28th so I'll be able to get some before/after dyno numbers to see what those headers can do - I was running 392ft lbs rw torque without headers so im hoping I pick up to over 400.