phrozen

I want to change the gears in my now stock 97 Z and wanted to know what would be the best choice for performance/economy. Shoud I go with 3.42 or 3.73? I know most people here use them but what's the real difference, where are they shifting?

Also, these will hopefully be coupled with a 2800 stall. This is all hopefull going on prior to the LT4 conversion.

QCKZ28

i recommend 3.73's, but beware i turn 3000rpm at 80mph in overdrive.

jesse

phrozen

so what do you shift at, thats what I'm really curious about. And do you have the stock torque converter?

CamaroGuy22

What do you have now 2.73's? or 3.23s?

If you have 3.23's then a swap to 3.42 is a general waste of money if you have 2.73's then i would say go fo rthe swap to 3.42. You want to look at traction, and what rpm you will turn on the highway. If you have a loud exhaust, and drive fast on the freeway you will not want 3.73's. Also if you run street tires and have traction issues currently, you can be assured that you will burn up the tires with the 3.73's. My car had 2.73's so i took the step up to 3.42's and it was a vast improvement.

phrozen

I've always kind of assumed I had 2.73's

I shift at 45mph out of first. does that help any?

Also the car is running street tires and right now I have very little problems with traction. The most this motor will probably ever put out is 450 to the crank, this isn't really a race car, just a fun car.

phrozen

ba-bump

Zack

check your shifter out. if "1" is selectable, you have 3.23's, if it isnt, you have 2.73's

phrozen

what do you mean selectable? my shifter looks like this

p
r
n
d
d
2
1

so does that means I have 3.23s since I can use 1?

Ace_437

Yep, you should have 3.23's. You can also check this by looking at your RPO codes. I can't remeber if 3.23 is code GU6 or GU5 though. Someone else will chime in and let you know for sure.

kingman109

GU2
Axle, Rear 2.73 Ratio

GU4
Axle, Rear 3.08 Ratio

GU5
Axle, Rear 3.23 Ratio

GU6
Axle, Rear 3.42 Ratio

Ace_437

What about GU3? I wonder why they skipped a number.

CamaroGuy22

You will find it alot more difficult to hook up on street tires with 3.42 or 3.73's even with close to stock power.