PZA

I have a 2001 Firebird Formula A4 with the stock 2.73 gears.

I am looking to upgrade my gears into something higher, and from what I've come up with 3.42's are my best bet since they are cheap and oem from m6 ls1's.

Now this is where Im confused. I keep reading that 3.42 gears will not fit into my a4. What else do I need? Do I actually need anything?

Thanks guys.

murphinator

iTrader: (2)

The carrier is different but you can get 3 series gears aftermarket to fit your 2 series carrier but...instead Just buy a 342 rear end from a junkyard out of a manual z28 for about $300 and install the whole thing and save or sell your existing rear saving money over a gear install with labor and then get something back for your existing rear to offset that cost while knowing gm setup the rear right vs. hopeing the shop you pick does it right....

Just make sure you match up 3 or 4 channel rear , if your car has traction control it's 4 channel , no traction control 3 channel

01ssreda4

iTrader: (96)

Just buy a ring gear spacer and stock 3.42s will bolt up. However, I personally wouldnt run a used gearset, go new instead. Motive GM75373x is what you want. You'll thank me later.

Blackpanther99

iTrader: (8)

Agreed^ Get then new and dont risk the chance of picking up some bad used gears. Then you gotta do the job again.

PZA

Thanks for everyones replies. I almost made a mistake and bought gears off craigslist. Right before I was going to pick up the whole rear end I read my door sticker and it turns out my car has the 3.23 performance gears from the factory....

Looks like gears is pushed back on my list of mods.

Fast98Z28

I went from 3.23's to 3.73's when my pinion bearing gave out. Was a good difference in getting out of the hole. I had a local shop do mine for 700 i believe. They used Yukon gears. Still holding up well for me, but i have heard some people say stay away from them.

Carl at CRP

iTrader: (9)

I've never heard or experienced anything but the best results with Yukon gears.

Carl