I have a pretty stock 89 IROC with the L98, 700R4, 2.77 gears, stock rims and stock size tires. I use my car for street most of the time, but may take it to our strip occasionally or hit an autocross. I place handling above acceleration as you can see by my mods list in my signature, but still want a bit better quickness than the boring 2.77s deliver.

I just got a #3 carrier and am about to order gears. I am thinking of either
3.45 or 3.70. What would you recommend ?

 

I swapped from 2.77's to 3.45's in my IROC. It's one of the best mods I made to the car. Wakes the car up. It's really a night and day difference.

 

3.27 or 3.45.

Nothing else available that makes sense. 3.08 is worthless, 3.70 is too much.

Those are your only choices. 3.27 is better all-around (street type variability), 3.45 is probably the lowest ET if your car has headers (will be slower than 3.27 if you still have manifolds). You can have A, B, C, or D; not much sense trying to get any finer granularity that what you can actually BUY.

Gears don't affect "handling". If that's what you want, look at tires, shocks, springs, sway bars, driver technique. A weeeeeeeeeeek car with a good suspension setup and a good driver will SPANK a powerful car that doesn't hook up and/or a driver that's clueless.

 

3.45 gears ordered, thanks for your input folks.


The sig line wouldn't let me list all my mods (almost lol) geared towards handling and hooking up. My Z handles amazing and launches great. Lets just say it surprises a lot of people.

Can't wait for the gears and carrier to arrive.

 

You won't be disappointed with the 3.45's. The 3.27's are good gears too. All of the V8 thirdgens should have at least come with 3.2x gears with posi-traction as a standard option. Even if your car was 100% factory stock swapping out the 2.77's for 3.27's or 3.45's would give you a great performance gain.

With the 3.45's at 70mph I'm turning about 2200rpm and a 80mph I'm turning about 2,500rpm. Still get decent fuel economy as long as you can keep your foot out of it.

With the 2.77's I was turning about 1900-2000rpm at 70mph and about 2200rpm at 80mph.

Whats nice is even after you get up to cruising speed the motor stays in the fat part of the torque band all the time. 1st gear is really fun with the torque of the L98, and the 3.45's with the 700r4's 3.06 first gear. As long as you have traction the car really with launch hard out of first gear and keep accelerating hard throughout the powerband. If you get a high stall converter that will help too. A converter that's in the 2,200rpm-2,500rpm stall speed range will work well with TPI. Stock stall is around 1,500rpm.

 

Thanks for that info yaj15.

Can't wait to get em in and feel the difference.

 

3.45s all the way......

I went to the 3.42s and love them.