2.5 L4 to 385 carbed-a few quick Q's
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2.5 L4 to 385 carbed-a few quick Q's
I am looking at an 84 Firebird with a 4 cylinder and 4 speed manual. I plan on installing a 385 and 700-r4. First, I know i will need to alter the wiring, but how much? Would it be possible to just take the ECM and the engine portion of the harness from an LG4 or L-69 car? I know of a place where I can get an uncut harness for cheap. Second, what mods to the driveshaft and torque arm will have to be made? Third, this car would have 3.42 gears, right? Finally, would this car's suspension be drastically different than a factory V8 car? I know i'll want to change out the springs and swaybars, but would I hurt anything just driving around with the original front springs for a while? Thanks in advance.
Joined: Mar 2000
Posts: 43,187
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From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Look for something else. Here's why:
1. A complete harness from a similar year V8 car is required, including ECM (if staying CC).
2. The driveshaft and torque arm should come from a car with a TH700.
3. The car may or may not have 3.42 gears. Although they were standard, most anything could have been ordered with the car. The only way to know for sure is to pull the cover and check the gears themselves.
4. The front suspension is quite a bit different from a V8 car. Springs, swaybars, even some frame braces were used on V8 cars that weren't on L4 or V6 cars. The V8 will give you a couple of inches front end travel at most with the L4 springs. No, don't try driving it with a V8 and the original springs.
The only sane way to do this is with a V8 donor car, preferably of the same year and brand, to provide all you need for the swap. Unless this thing is in absolutely immaculate shape and you get it for free, it isn't worth it to get it with the thought of doing the swap. You're much better off getting a factory V8 car and putting your big V8 in it.
The only thing of value this car appears to have is the 3.42 rear. That makes it a good parts car, but until the supply of factory V8 cars is exhausted, economically it isn't a good V8 candidate.
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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. '66 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 600 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).
1. A complete harness from a similar year V8 car is required, including ECM (if staying CC).
2. The driveshaft and torque arm should come from a car with a TH700.
3. The car may or may not have 3.42 gears. Although they were standard, most anything could have been ordered with the car. The only way to know for sure is to pull the cover and check the gears themselves.
4. The front suspension is quite a bit different from a V8 car. Springs, swaybars, even some frame braces were used on V8 cars that weren't on L4 or V6 cars. The V8 will give you a couple of inches front end travel at most with the L4 springs. No, don't try driving it with a V8 and the original springs.
The only sane way to do this is with a V8 donor car, preferably of the same year and brand, to provide all you need for the swap. Unless this thing is in absolutely immaculate shape and you get it for free, it isn't worth it to get it with the thought of doing the swap. You're much better off getting a factory V8 car and putting your big V8 in it.
The only thing of value this car appears to have is the 3.42 rear. That makes it a good parts car, but until the supply of factory V8 cars is exhausted, economically it isn't a good V8 candidate.
------------------
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. '66 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet, GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 600 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).
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