I have a 92 caprice with 2.73 gears. Can the gears be changed to 3.43 without changing the whole rear end? Or is that just the cheapest route to to go? I.E finding a car in the junkyard with them already in the rearend.

 

Does it have the 8.5 10 bolt or the 7.5 10 bolt? The 8.5 rear end uses a 3 series differential for the 2.73 gears. You can install the 3.42 gears without changing anything else. I recommend getting a good installation kit to make the job of setting up the gears much easier.

If it has the 7.5 then you might want to find an 8.5 and do a complete swap.

 

I really dont know. I went through the SPID's and the codes for that are not on my sheet. G86 8.5 G87 7.5 and there are a bunch of Y codes also which I dont have. And a double check shows I have 2.56 rear gears

 

Look at the bottom of the housing. If it has the 8.5 then there will be a squared corner on the bottom of both sides of the casting where the cover bolts on. If it's the 7.5 then it will have a small tab sticking out with a machined radius cut into it. The squared corners are easy to see on the 8.5 when you look under the car.