Hey guys, so i have a 2.2 manual trans on 32's. I really want to re gear my dime. But, IDK what the difference is between the GM 7.5 in and the GM 8.5in. Can someone explain to me what the difference is and which one I am suppose to use?
Here are two gears that I was looking at on summit

http://www.summitracing.com/parts/RMG-6903241/

http://www.summitracing.com/parts/RMG-6901671/

Thanx

From what ive researched the 7.5 axel tubes go straight into the housing and the 8.5 have a bulge where they go in.
Here are some google images.

http://images.google.com/images?hl=en&q=how%20to%20tell%20difference%20between%20chevy%207.5%20and%208.5&um=1&ie=UTF-8&sa=N&tab=wi

Also use this to  for your gear choice.

http://dezertdimes.com/forum/index.php/topic,3279.0.html

That's the exact one I used when I ordered my gears. Will have the entire new rear end installed this weekend.

So are you saying that I can use either/or?  And when you say "bulge" what do you mean?
Thanx

From what ive researched the 7.5 axel tubes go straight into the housing and the 8.5 have a bulge where they go in.
Here are some google images.

http://images.google.com/images?hl=en&q=how%20to%20tell%20difference%20between%20chevy%207.5%20and%208.5&um=1&ie=UTF-8&sa=N&tab=wi

Also use this to  for your gear choice.

http://dezertdimes.com/forum/index.php/topic,3279.0.html

The two rear ends are different. As long as you have the stock rear you should have a 7.625 rear. The 8" ring and pinion set will not work with your differential and even with the 4.56 gear set you still will not be back to the stock tire to gear ratio set up and our 2.2's really need as much help as possible.

Yeah you more than likely have a 7.5 Not a 8.5 I was just trying to give you a visual of  how they differ in appearance, so
you could identify yours as one or the other.
7.5 Axel tubes are the same diameter all the way into the housing         
8.5 Axel tubes get larger in diameter where they enter the housing.