3.55 ring & pinion

Tnx for the info GoldDuster. I didn't know they had 2 different levels. Never saw anything except what I have advertised. I just picked up a real nice used set of factory 3.55's I'm going to put in a 489 case I have and put them in. About the same time I'll be putting in a stout 408 so I won't really need the lower gears anyway. Your probably right about them lapping in after you drive them some. When I pull mine back apart I'll check them and see if I can get them better. You know the funny thing is when I set mine up I set them up favoring the drive side thinking that would be best and it's only while cruising at 45-55 mph that it's noisy. Even though the coast side was off more than the drive side it's completely quite while coasting down. Go figure! I'm also installing some dynamat in the rear hatch area to help keep it quieter. LOL

I'm kinda surprised to hear your GTO has some gear noise. Usually new stuff is without noise. Guess it's cause it has perf. gears in it.