Hey folks,
I'm building an 84 bird and my goal is around mid 13's in a totally streetable, stock looking Firebird S/E. The V6 5 speed is gone in favor of a 350 or a 400. My questions are, what would your recommendations be for engine components, should I go with a 400 or 350(reliability issues?), and what tranny? I have a 700R4 with a fresh rebuild out of a 350 equipped GTA, but I could get a T-5 or a TH350. Also, I will need a rear-end that will be driveable yet stout enough for a 13 second car. I am thinking a 3.23 rear gear because the car will be built in Arkansas and driven back to Indiana after the build-up. Any opinions would be appreciated.

Thanks,
Chris

 

Tranny should be a no-brainer - TH700. You'll want a convertor that stalls above stock but retains the lockup function.

The only replacement for displacement is non-normally-aspired - so, no NOx or air pump means go with max cubes. Reliability isn't an issue between 350 & 400, although it could be argued that the 400 will make more power at fewer RPMs, so should last longer.

You really shouldn't pick components based on the drive home from the shop. 3.73's make the most sense for ET's, 3.23's if primary use is driving. Pick 'em based on how you'll use 'em. If you don't like the thought of driving a few hundred miles with 3.73's, trailer it home. The 10-bolt will probably take your power level, but you'd be wise to optimize it as detailed in the tech articles.

The first challenge is making the power, the second is getting it to the ground without breaking anything. Sub-frame connectors are a must, good suspension components like those from Spohn next.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/'87 LB9 block, ZZ3 cam and intake, World 305 heads, Hooker headers & y-pipe, 3" Catco cat & 3" cat-back).
57 Bel Air, my 1st car. 0.030 over 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlock header mufflers, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Best 15.1/94.6 @ 5800' Bandimere.

 

Thanks 57!
I'll use the 700R4 then, since I have it and probably work with the 400. I've heard that the stock heads on the 400 really suck, so I'll need a cost effective upgrade there. My experience with 3.73 gears was with a TH350 so maybe the 700R4 won't be too bad. I'm probably going to snag a 4th gen rear with discs, so it should hold up to the power being made by the 400. I agree with you about the SFC's they are a must have item. Luckily though, I'm building a hardtop car, so we will start out a little more rigid. What size/brand of carb would you recommend? Intake? Do you think this combo with the 3.73's will take this car into the 13's? Into the 12's with Juice? I will be building it so that the internals can handle whatever power adders I can throw at it, so that won't be a problem. With this added need for fuel, I will probably need to upgrade the fuel pump as well, correct. The car is currently carbed, so the change-over shouldn't be too rough.


Thanks,
Chris