Re-Gearing the differential???

I am currently going from a V6 to the L98. Correct me if I am wrong but I will be going from a 2.73 gear to a 3.42 gear. I was planning just taking out the old stuff and putting the good stuff in. Am I going to have to change the diff housing or can i just use the same one? Thanks for ur time.

You can't just swap parts out, there is gear setup involved using tools like inch/pound dial torque wrenches, dial indicators, etc. If it isn't done right, it's going to be noisy or outright fail.

See if you can find a rear with a decent ratio already in it. That is a much easier swap. If not, might be best to pay a professional to install the gears.

OK, since you are wrong, I will correct you :)

Most V6 cars came with 3.23 or 3.42 gears stock. No need to upgrade the gears. However they usually came with an open differential. You will want to upgrade that to a positraction unit.

I appreciate the correction but I looked through my shop manual and the books said if i had a 3.23 or 3.42 i would have disc brakes in the rear. i dont have any but i want some though. so if i read this right i have either the 2.73 or 3.08 gears. the ring gear is pretty much the thing that i need to worry about fitting and that says 7.62" for all diff's. I would read the axle code but that is too far gone to read. i have done diff work before and i know how precise u have to be. i want to go posi but right now i am on a budget to get this baby back on the road again. Thanks

Why not turn the assembly over by hand and count the revolutions? Or remove the cover and count the teeth?

Why not turn the assembly over by hand and count the revolutions? Or remove the cover and count the teeth?
screw counting the teeth, pull the cover, and give us the numbers on the edge of the ring gear

If you are starting with a v6 you will have a non-posi drum brake rear end with 3.23 or 3.42 gears.

The best approach would be swapping out a posi unit with the desired gears and disc brakes.. You will have traction problems with the l98's torque with the non-posi.

get yourself a rear end out of a 4th gen. you will have disc brakes, posi, better gear ratios, etc. Its a very simple and straightforward swap.