[Darkbrute69]

i have a gm 7.5 rear differential in my 1967 firebird and it has 2.73 gears and was wondering should i change the gears to better ones or change my whole rear differential to a 8.2 or 8.5 differential? thank you

 

[big gear head]

If you are making more than 200 HP I would change the whole rear end. The 7.5 isn't much of a rear end and was originally designed to use behind 4 cylinder Vegas. The BOP 8.2 that was used in the 1st gen Firebird was a modified Tempest rear end and was 1 inch wider than the Camaro rear end. It was also a little stronger than the Chevy 8.2 10 bolt. The Camaro and Nova rear ends will bolt into the Firebird, but will be 1/2 inch shorter than the BOP 10 bolt on each end. The 8.5 will probably require drive shaft modifications. The pinion shaft is about 1 inch longer on the 8.5.

 

[dwwl]

Don't waste time, money, or headaches on anything but the 8.5 10 bolt. Find the gears you want, and a possi and you got it made. The only thing I will say, is get the newer type wheel bearing that move the bearing location on the old axels when you redo it. Normally the location where those bearing sit on the axel have years of wear.

 

[big gear head]

The only thing I will say, is get the newer type wheel bearing that move the bearing location on the old axels when you redo it. Normally the location where those bearing sit on the axel have years of wear.

Got to disagree with this. The "axle saver" bearings have caused nothing but headaches with me. I installed them on an El Camino of mine, and on a few customer's cars and trucks and had to go back and replace and repair almost all of them. Once you get them in they are very hard to get back out, and about 90% of them leak oil onto your brakes. If the axles are worn then fix it the right way with a new set of axles and the correct bearings.

 

[dwwl]

I used them in my nova and haven't had a problem at all. I wonder if there are different brands or makers of them. I don't recall who or what company made mine because it was a few years back and I didn't record those facts. Maybe I just got lucky. I know I had to special order them, and had to wait a couple of days. Maybe i'll check the net and see if there are any problems reported on them.

 

[JJLT1]

x2,
depending on your power level and driving style, anything above a grocery getter,
if you have a choice on a 7.5 and something else, go with something else..
after you spend a 1000$ on a 7.5, its still a 7.5..

 

[Transmech]

I too have used several of these as a cheaper alternative on those types of repairs. I have not had any problems with them leaking, but I do notice that because of the added length of the saver bearing that sometimes it is hard/harder to get the axle pushed in far enough to get the c-clip back in.

I personally would never use them in a vehicle that I own/drive but when given the cheaper alternative to replacing the axle/seal/factory bearing, most of my customers choose the axle saver.