Hello I have a 1985 Buick Le Sabre with 307 V8 and 4-speed automatic. I was wondering if anyone knows the standard rear axle ratio for the car? I checked the RPO codes on the trunk sticker (as I do not have the sales sticker) and they simply indicate that it has the standard axle ratio, with 7.5 inch pinion gear.
I'm assuming that it is geared ungodly high judging by my slow acceleration (slow even for a 307, and yes I am familiar with them). I want to upgrade to at least 3.08 or higher. What is interchsngeable between Buick-Olds-Cadillac-Pontiac-Chevy-GMC? And do I need to use something with 7.5 inch gears or can I use the bigger size too (which I can't remember off the top of my head)? Guess my main concern is that my axle shafts will match up too.