WsXs3

whats involved in swapping a 91 firebird from a 3.4/slushbox to a 350 tpi with a t-5 backing it?anything major I should look out for, any tips? any help would be appreciated. its still in the early stages of development and im just getting an idea of what im in for.. thanx guys for helping out a n00b

Dyosis

Not real sure about the electrical setup but you will have to change out your motor mounts and what not. You will also probably have to drop the gas tank and put a new fuel pump in it and possibly run new fuel lines. There is alot more info on thirdgen.org about v6-v8 swaps, so you might want to check it out.

Just a personal opinion, you might want to look into getting a T56 tranny over the 5 speed setup. The 3rd gen 5 speed trannys were not paired to a 350 for a reason at the factory, they are pretty weak. If you do decide to go with the 5 speed, you will be replacing it down the road.

85_305

First of all, good luck finding a T5 that will handle the torque of a 350 for very long If you decide to go w/ a standard, you will either be looking at a T56 or a Jet or Tremec or something.

Crovax WS-6

well first off the 91s never came with a 3.4 its a 3.1 Second of all. If you are gonna do this swap. Why not go for a 383 and a 6 speed. i have a t-5 behind my 355, and i just roasted my 10 bolt. I dont know how much longer the t-5 is gonna last. you are better of gettin a t-56 and saving your self the trouble. You can get a used one out of a 4th gen and al the swap hardware for prolly 1500 -1800$ and if i were you i would go carburator. It will eliminate the wireing cluster **** that you are gonna have to go through unless you get a full harness with the engine. my .02

85_305

That Much For A Used Tranny?????????

Crovax WS-6

well you also need a new clutch, new pressure plate, New cross member, possibly a new torque arm but im not sure on that one. the correct Bellhouseing. Cause if you get one from an LS-1 it wont bolt up. Theres more then just the trans that you have to buy. plus if he is goin from auto to stick hes gotta get all the hydraulics, the pedals, a console plate or console, a shifter. it all adds up pretty quick.

respectirocz

if u dont mind spending like a 100 bucks, u can get a wiring harness from painless, and in my opinion wiring harnesses are no tht had, especially when they're labeled, , just like eveyone says the t5 ont handle the torque of a 350, so it was only paired with the 305,
unless i'm mistaken the bolt patern on an lt1 is identical to the standard small block chevy, so if u get a t56 from a 93-97 f-body u can just bolt it in

also i think but i'm not sure, that since the t56 is a longer tranny than the t5 u need a shorter torque arm, but again i'm not sure about that, and like said before, if the car was originally an auto, u need the pedals, and hydraulics, and the center consol, cut a nice big hole for the shifter, etc etc

87z-28man

i just did pretty much the same swap your talking about. i took a 350 and swapped it out for the siezed up 305 original in my IROC and kept the original T-5. i'm definatly planning on swapping for the T-56 down the road, not sure how long, as long as the T-5 stay's put. ive been reading alot and if you are going to do the T-56 swap, you dont need the whole center console, just cut the shifter hole open about 2 inches back farther and it'll clear everything just fine. and make sure you get the everything from the donor car, tranny, slave cylinder, hyd. linkage, pedals ect. try to get the setup from a 94-97 camaro/firebird, those bellhousings bolt right up to the standard 350. your also going to have to either fab. up a new tranny crossmember or buy an aftermarket one. like Crovax said, go with a carb'd setup. it'll get rid of the wiring pain in the butt unless you like wiring stuff up.

if your intrested, heres a helpful site on the T-56 swap

85_305

^If you cut the shifter hole open 2" more, you will have a big gap in your console wont you? I dont see how that would work/fit?

doug791

it does. Havent done or seen the swap so i cant explain it but i know it does

91-Z28-L98

I don't know too much about the tranny swap, but for the engine you will need new V8 engine mounts, new springs to support the heavier engine, maybe a new radiator and hoses, and of course the wiring harness. The fuel lines and pump should work fine. My friend had a 2.8 v6 and the engine and tranny crapped out on him so he swapped in a 305 TBI for the sake of cheapness to get the car sold. The biggest problem he had was that he had to bypass the vehicle anti-theft system on the new computer because his old ignition system didn't have the chip sensor in it. The fuel pump and lines worked fine, even with the lower pressure TBI injectors.

85_305

So there isn't a gaping hole in the console?

iansane

You don't cut the hole in the plastic console itself, you cut the hole in the metal floor/tranny tunnel.

mrr23

and don't forget to swap the front springs as well to v8 springs.

85_305

Ahh, ok.
How much of a pain in the ace is it?