Hi y'all,


So i wanted to post this a few weeks back, but i wanted to make sure the deal was going to go through before i said anything.


So about a couple of months ago i had ask which route should i take my 92 Firebird v6. But it didnt really go far. So initially i decided tot go with a 383 Stroker, but my budget went over the limited when i quoted everything. So what i have thought was to buy each important component individually. But i came across a deal i couldn't pass.


Well, me and my dad own a tranny shop. One of our usual customers had a car with a bad engine. He didn't have enough to rebuild or replace. But what he did have is a kind of beat up 2000 Firebird with the LS1. He was going to sell the car because it got in a minor fender bender and he doesn't want to fix the body. So i offered him a trade, a new rebuild engine for the Firebird.


So its a deal, to day i gave him his car back, and he brought the Firebird.
The body is in rough shape, but im not to worried, i only need the Engine and Tranny and what ever may bolt on.


So with that, this brings me to my question.

Besides the engine and transmission(4L60E), what else can i use to bolt on to my 92 Firebird? I want to use as much as possible. Rear? Driveshaft? Front End Suspension? Crossmamber, Cradle??

Also: What is the best Harness to use? Please if you have videos or pictures, please share.

Also

Please chime in with your 2 Cents.


Thank You, All.

 

You can use a lot, depending upon how willing you are to do some fabricating to get it to fit.

The complete engine/transmission harness should be used. The chassis side fuse/relay boxes can also be used, although they will have a lot of things you won't need (like headlight). I've done 3 LS swaps (2 in 3rd gens), used the factory fuse/relay box on one (the only one for which I got the factory box) and preferred that route. I spent one evening removing the stuff that wasn't needed from that harness and rebundling what remained. You will have to do some splicing into the 3rd gen harness regardless.

The driveshaft fits.

The seats fit.

The fuel tank "fits" with some modifications to the fill tube (cut the rubber piece an inch or two), wiring (you can use the harness from the donor car, but you'll have to splice it into the 3rd gen), and fuel lines (I fabricated new lines with aftermarket disconnects on the tank fittings). If you do an emissions-legal swap, you'll have to use the donor car tank.

Many TGO members have swapped the 4th gen dash into their 3rd gen. Modification/fabrication required. Ditto for the center console. The 3rd gen and 4th gen sending fuel units and gauges aren't compatible with each other, so one of the reasons for the 4th gen dash is to have functioning gauges with the 4th gen drivetrain, tank, and emissions equipment.

If your 3rd gen is automatic, the factory sifter and cable will work better than trying to modify the 4th gen shifter. But, with some fabrication, and if you use the 4th gen center console, the 4th gen shifter will work.

You can use the donor car rear end, but it is longer than the 3rd gen rear, and isn't any stronger. But, the 4th gen probably has posi, and your 3rd gen probably doesn't.

The 4th gen front brakes can be modified to fit the 3rd gen. Or maybe it's the 3rd gen can be modified to fit the 4th gen brakes...

The donor car radiator and fans can be mounted into the 3rd gen. But, your 3rd gen radiator is adequate to cool an LS1 (although it's single fan, if memory serves - dual fans are nice). I used 3rd gen radiators and dual fans in my LS swaps.

Some members have used the 4th gen radiator overflow reservoir in their 3rd gen. You have to cut the battery tray to fit it.

You will have to buy or fabricate engine and transmission mounts.

The 4th gen cat-back can be made to fit 3rd gens. The 4th gen Y-pipe won't fit, though. The donor car exhaust manifolds will fit.

There's probably more, but that's what comes to mind off the top of my head.

 

Five7 said it all really.

Def use the brakes!! Check out bigbrakeupgrade for the conversion parts. Very reasonably priced and trust me when I say...putting the LS1 brakes on is just as dramatic an improvement as tripling the horsepower I HATED my stock thirdgen brakes.

I like using the LS1 radiator because of the fans, and if you use the LS1 A/C parts, the condensor will clip right onto it making for an easy install. Also....you have the steam vent hook up right there for you. I was able to make the LS1 rad hoses fit just fine as well.

Speaking of A/C...you can use the entire A/C system if you get a little creative with the EVAP box. Check my old threads to see what I did. Since it sounds like you work in a shop or have access to shops, you could probably have your stock evap outlets modified with some creative brazing and not even have to modify the HVAC box like I did. The LS1 A/C system is pretty compact, and works quite well.

Im not a fan of the overflow. Some have managed to mount it UNDER the battery tray. If you mount it like it is in the LS car, you'll need to cut a HUGE hole in the battery tray. I honestly like the look of a new coolant reservoir mounted in the stock spot, but if you want it hidden, use the LS1 bottle!

Since you have a firebird, you can also use the LS1 washer bottle and make it super stealth. With a little work, you can mount it under the hood latch support and just have the cap visible.

Cat back will 100% fit up until the y-pipe area. Make sure you take the rear most hanger hardware off the LS1 car. Once you do that, virtually any exhaust for a 98-02 will fit right up. I made the mistake and got a 93-97 catback, and ended up converting it to 98-02 by welding hangers on my nice brand new stainless exhaust tips

From mid car back, both cars will be identical. ALL of the hardware for the rear suspension, including the actual panhard bar and brace will bolt right into your 3rd gen. And most if not all of those bolts will be in better shape. So when you strip the LS car, organize and label all of those bolts. You can use them!

Keep bits of the wiring too. When/if you have to extend a harness, or hook up gauges, etc, its really nice to be able to match wire colors, and use good grade factory wire. I used a ton of wire from my donor for odds and ends and extensions.

Good luck! Make sure to take lots of pictures and post em!

J.