Sterlingsxe

This guy i want to buy gm motive 3.73 says i need to have a series three carries how do i kno which one i have i have a 94 z28 LT1. Help me out on how i can tell. THank you

RamAir95TA

If your car originally came with 2.73s, you have a 2-series carrier. 3.23+ require the use of a 3-series carrier (but there are 3.23+ gears that will fit a 2-series carrier).

Sterlingsxe

i got my car used i dont kno wut it came with how do i check/

RamAir95TA

If you have an M6, you have 3.42s.

If you have an A4, check the RPO codes in the glovebox or on the door jamb.

GU2 - 2.73
GU4 - 3.08
GU5 - 3.23
GU6 - 3.42

Sterlingsxe

so just the 2.72 is a series 2 the other 3 are 3.23

RamAir95TA

All cars that came with 2.73s have a 2-series carrier.
All cars that came with 3.23+ have a 3-series carrier.

Sterlingsxe

Ok it said gu 5 wutever so i have 3.23 is it going to be that much imporvment is i go to 3.73? Is it worth it?i have an A4

SWINGRRR

You cant gauge improvement just on that statement. You purchase gears after evulating what you have. Gears will help keep an aftermarket cam in the power band, look at your tire size, how you drive you car, etc., etc. You dont want to buy gears and be going down the highway at 5500 rpm's in second gear! I am not saying 3.73's will do that, but you have alot of factors to consider.

12sec97Z28

I thought 3 series carriers were for 3.42+? I'm not positive because I had a 3.42 stock anyway, so I knew what I had. Not arguing, just asking. Plus, I haven't dealt with a 10-bolt in a while now.

shoebox

The factory carrier for 3.23s is a 3 series carrier.

12sec97Z28

Thanks Shoe. I guess i was a little confused on that.

Sterlingsxe

LoL you people look at everything. Would u go from 3.23 to 3.73. I dont have a cam yet but i am going to be purchasing the 305 soon enough.

12sec97Z28

definitely. i think it's pretty well agreed that a gear is one of the best bang-for-your-buck mods you can do. i went from a 3.42 to a 4.10, and it changed the car's whole personality. 3.73 is a good gear for a 4l60e car. just know that the speedo will be wrong and it may shift incorrectly until you get a hypertech, get your computer reprogrammed, or get some other kind of calibrator.

Mtrhds94Z

I have also never seen 3.08's in an fbody...

shoebox

...and you won't in a 4th gen. However, the option code does exist, even if it was not used on our cars.