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What motor for my 85 Firebird?

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Old Dec 18, 2003 | 08:54 AM
  #1  
75/92 Birdman's Avatar
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From: Raleigh, NC
Car: 1998 Trans Am, 1992 Firebird
Engine: 402 LS2 stroker, 355 SBC
Transmission: T56 in both
Axle/Gears: 4.10 gear Moser 9", 3.27 9-bolt
What motor for my 85 Firebird?

OK, this car will be mainly a road race car to showcase my business. I am setting the suspension up, interior will have a 8-pt cage, no stereo, automatic tranny (for now, manual will come later), 10-bolt with posi, etc. Right now it is a 2.8L car, but I am swapping in a bigger motor. Here are my options: L98, LT1, LS1. L98 and LT1 would be good because of their low-end, but a LS1 would be trick. Of course, a well built L98 would come out less than either of the other two motors and will probably be more powerful. What would you guys do?

This car is gonna be sick, 91-92 Formula clone, electron blue with an ASCD ram-air hood, silver ghost flames coming off the nostrils, SLP 3rd gen Firehawk wheels(I think, might get some different ones). Once I get this crappy 78 TA out of my garage and get my other cars sold, this one is coming to my house and I am starting the work on it.
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Old Dec 18, 2003 | 09:03 AM
  #2  
75/92 Birdman's Avatar
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From: Raleigh, NC
Car: 1998 Trans Am, 1992 Firebird
Engine: 402 LS2 stroker, 355 SBC
Transmission: T56 in both
Axle/Gears: 4.10 gear Moser 9", 3.27 9-bolt
Man, it has been forever since I've been here, my signature had two cars that I sold over a year ago in it!
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Old Dec 20, 2003 | 10:00 AM
  #3  
TKOPerformance's Avatar
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Joined: Dec 2003
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From: Newark, DE
Car: '86 Camaro, '02 WRX, '87 K5, '67
Engine: 350 TPI, 2.0turbo, 383 in the works, 289-4BBL, 232, A-head 4-cylinder
Transmission: T56, 5-speed, 700R4, C4, T176, semi-auto 2-speed
Axle/Gears: 3.73, 3.90, 4.88, 3.55, 3.54, 7.00
I'd go with the LS1. It's a better engine than all the others, and it will look super trick for a showpiece car. I would do the motor and trans swap at the same time and just use a T56 from an LS1 car. Otherwise you'll have to do all sorts of finageling to get a normal small block trans to mate with the LS1s unique bolt pattern, and then udo it all when you swap in a manual trans.

There are swap components out for this conversion already. You will need to modify the K-member for AC compressor clearance if you want AC, otherwise you may just be able to run a shorter belt and bypass this part of the swap. The motor mounts can be purchased, and everything else sounds fairly simple. It will be easier to drop the whole motor and trans out of the bottom of the car and then reinstall the LS1/T56 combo wiht the K-member already bolted in place.
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Old Dec 29, 2003 | 09:46 PM
  #4  
kfoley's Avatar
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From: New Palestine, IN (Just East of Indy)
Car: '85 Z28
Engine: 305
Transmission: WC T5, 3.23 posi
I'd say LS1. It's lighter and will help with handling.
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Old Dec 30, 2003 | 07:13 AM
  #5  
75/92 Birdman's Avatar
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Posts: 250
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From: Raleigh, NC
Car: 1998 Trans Am, 1992 Firebird
Engine: 402 LS2 stroker, 355 SBC
Transmission: T56 in both
Axle/Gears: 4.10 gear Moser 9", 3.27 9-bolt
Well, I've decided on an LT1/T56 combo. One of my customers gave me a complete LT1, so all I have to do is buy the T56 setup and put it all together. That way I can focus more on suspension and chassis rather than spending all my money on an LS1.
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Old Dec 30, 2003 | 11:48 PM
  #6  
Project: 85 2.8 bird's Avatar
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From: BFE, MD
Car: 13 Ram 1500/ 78 Formy
Engine: 5.7 / 7.4
Transmission: 6sp / TH350
Axle/Gears: 3.55 posi / 3.23
LS1's aren't that much more in weight than the 3800 Series II, nudge, nudge,
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