There are 3 rear ends that will bolt into a firts gen Camaro. The 8.2 and 12 bolt were available in these cars, and starting in '72 the Nova and other X body GM cars got the 8.5 10 bolt, which will also bolt into the Camaro. There are 2 different leaf springs, mono and multi. The spring perches on the rear end are made for one or the other, so your springs need to be right for the perches on the rear end.
The 8.2 10 bolt has a 1 1/8 pinion nut and 3/8 ring gear bolts with 9/16 heads. The 8.5 10 bolt has a 1 1/4 pinion nut and 7/16 ring gear bolts with 3/4 heads and left hand threads. The covers on these rear ends will interchange, so you can't go by that. I have 2 of the 8.2 rear ends with 8.5 covers on them.
Posi IS limited slip. Posi, Positive Traction, Sure Grip, Duragrip, Traction Lock, Power Lock, Safety Track... are all trade marke names for limited slip differentials made by different companies. Posi is Eaton's name and became so popular that it became the generic name for all limited slip differentials.
All of the limited slip differentials listed above are clutch type. A locker doesn't have a clutch like these. It works similar to a ratchet with steel teeth instead of clutch plates or cones. They work very well and will not slip under power for any reason. The only time they will allow one wheel to turn at a different speed is when turning. They make more noise than the clutch type units and they make the car jerk a little sometimes, but for drag racing the only thing better is a spool.
Internal parts to the 9 inch Ford Detroit Locker
9 inch Ford spool
Dana has been making rear ends for many years. The Dana 60 was originally a military rear end, but started being used in 3/4 and 1 ton trucks many years ago. They were used in Chrysler muscle cars in the '60s and early '70s with the Hemi and 440 6 Pack 4 speed cars. They are very tough. Dana makes many differenti size rear ends, like the 25, 30, 35, 44, 60, 70 and 80. They are used in everything from Corvettes to 2 ton trucks to Jeep Wranglers.
The 9 inch Ford was used from '57 to the mid '80s in Ford cars and trucks. It is called a 9 inch because the ring gear is 9 inches in diameter. That is the way most rear ends are identified. The 9 inch has a removable case that drops out from the front side, which makes it a little easier to work on. The 9 inch is a very strong rear end if built right. In stock form most of them are not much stronger than a good 10 bolt. The 9 inch has MANY after market parts available for it. You can easily build a 9 inch without using one Ford part in it.
As for the Eaton posi, I think it is the best street/strip differential you can use in a GM car. It is rebuildable, tunable, strong and works very well.
Eaton posi for the 12 bolt Chevy
