I have a 72 Camaro apparently the year they switched sizes, How can I tell if I have a 8.2 or a 8.5, Thanks David

Camaro switched from the 8.2 to the 8.5 between the 70 and 71 model year, so yours would be a 8.5.

Nova still had the 12 bolt in 71, so they might have had some 8.2 rears in 71 too.

Chevelle made the change late in the 72 model year.

Thanks Gary,

8.2 has 1 1/8 pinion nut and 3/8 ring gear bolts with 9/16 heads. 8.5 has 1 1/4 pinion nut and 7/16 ring gear bolts with 3/4 heads and left hand threads.

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'69 RS/SS396 Pro Street
427 4 speed 9"
Byars Performance
High Performance Drive Train Parts And Service
www.lubedealer.com/biggearhead (http://www.lubedealer.com/biggearhead)

[QUOTE]Originally posted by big gear head:
[B]8.2 has 1 1/8 pinion nut and 3/8 ring gear bolts with 9/16 heads. 8.5 has 1 1/4 pinion nut and 7/16 ring gear bolts with 3/4 heads and left hand threads.

are the pinon flanges interchangable? I just recently swapped a 10 bolt for a 10 bolt and realized after the swap my drive shaft would not fit. I am in the process of removing the old flange to see if it will fit. but am having trouble getting the new flange off. any suggestions. thanks

If both rear ends are the same, 8.2 and 8.2 or 8.5 and 8.5, then you can swap them. You can not swap an 8.2 with an 8.5. The pinion shaft on the 8.2 has 25 splines and the shaft on the 8.5 has 30. The early 8.5 used the same 1310 series u joint as the 8.2 and 12 bolt.

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Byars Performance LLC
High Performance Drive Train Parts And Service
www.lubedealer.com/biggearhead (http://www.lubedealer.com/biggearhead)

[QUOTE]Originally posted by big gear head:
[B]If both rear ends are the same, 8.2 and 8.2 or 8.5 and 8.5, then you can swap them. You can not swap an 8.2 with an 8.5. The pinion shaft on the 8.2 has 25 splines and the shaft on the 8.5 has 30. The early 8.5 used the same 1310 series u joint as the 8.2 and 12 bolt.

I removed the 8.2 and swapped in a 8.5, the 8.5 pinion flange is bigger. What options do i have? shorten the drive shaft and change the u joint or find a 30 spline pinion shaft? thanks for the help

If you need a yoke for the 8.5 that uses the 1310 u joint then you need an 8.5 yoke from an early '70s rear end. Look for a yoke that has the small tabs just outside of the u joint caps that locate the u joint, not the type that has the retainer rings on the inside of the yoke.

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Byars Performance LLC
High Performance Drive Train Parts And Service
www.lubedealer.com/biggearhead (http://www.lubedealer.com/biggearhead)