So, I just recently purchased a 1986 firebird with the 2.8 V6, 5 speed, and I've been considering doing a swap to either a 350 or 383 when I get back from my deployment next year. Basically, I want to compare motors, prices, performance outputs, the like between the two, and I wanted some actual human response other than just technical jargon. Also, what all I would have to do to complement the engine swap (Drivetrain, chassis reinforcement, etc.). I'm pretty new into the whole working on cars thing, and what I do know is pretty much restricted to rotary engines, so I'm completely lost here, haha. Any help would be greatly appreciated.

 

cost difference between a 350 and 383 is very minor. Unfortunatly your going from a v6 to v8 ( like i did ) and will need all the accessories the v8 has. Since you have a 5 speed am pretty sure you lucked out and have a posi with 3:73's, atleast my old v6 camaro 5 speed had that rear. Tranny and rear will work, but too a certain point before they start breaking with the power.

Whats your goals of power output? street only, street/strip? Carb or FI?

Right off the bat your going to need

- motor mounts from a v8 ( need to relocate them, which your gonna have to relocate your front brake lines, mise well just change them while the motors out )
- Serpentine system or V belt system from a v8

I had fun doing my swap, but there was alot of work to do and alot of man hours if you have never done one before. Take my advice and label and organize all of your bolts. Should save you a few hours of work trying to find the right bolts. Take it from me, i didnt do it lol

 

Your also going to need V8 front springs, the rear has 3.42s stock, unless it's modified. V6 tranny will not work unless you change the bellhousing and the input shaft.

 

oops, forgot bout the bellhousing :P

everyone says you NEED v8 front springs....Iv'e done this swap twice, first one was v6 to 305. Then my most recent, v6 to 383. I didnt change my front springs on my camaro, and i didnt change them on my firebird. The stock springs worked just fine and drove just fine. I live in jersey, roads are horrible! but i never once had a problem. Is it a good idea to change? probably, but its not needed to complete the swap....

 

I say it because that's what I've heard. But I haven't gotten to go to a V8 yet.

 

if you are going fuel injection you will need a new fuel pump. easy way out will be a carb. if the replacement motor has a lot of power i would suggest lca's, sfc, new suspension components so the car doesnt twist under torque and/or crack a windshield. tranny i would trash the t5, there was a reason why they were not behind anything bigger than a 305. u can do a t56 though if i were doing street/strip car i would get a th350,th400, or a 700r4. also if u are going fuel injection u will need a new brain box. along with all the acc. like stated above.

 

I'm definitely looking to go carb, and I think I've decided on the 383. I'd love to go straight LS conversion, but I think I'll get this one done, maybe consider an LS later on. And it's definitely not gonna be for racing, more for street. Hoping to get this project rolling soon, thanks for everyones inputs and help.