I have a 70' Skylark with what I think is the original 8.2 rear and a 72' skylark with what I know is a 8.5 and the drive shaft if needed. My uncle gave me a 3.42 gear out of what he thinks was a 10 bolt 8.5 Chevy (Camaro) I think. I am trying to get to a 3.42 posi rear. Will the gear work in my 72' rear end and if not what is the least expensive way to get there?
As far as I know, 8.5 stuff is interchangeable. If the 3.42's are in fact 8.5 gears, all you need is an aftermarket 8.5 posi. Install it in your 72 Skylark rear.
When going from the 8.2 to the 8.5...you need the driveshaft from the 72 Skylark. While you have the 8.5" apart, go through or have someone like Jim/Monzaz rebuild it.....also a good time to install rear bushings, boxed lower arms and rear sway bar.
Any GM 8.5 unit yes but there are 2 series and 3 series...Get the correct one for your ratio application... 2 series are : 2.41 2.56 ratios 3 series are : 2.73 2.93 3.08 3.23 3.42 3.70 3.73 3.90 4.10 4.30 4.56 4.88 5.13 5.57 You can use a 2 series with the correct spacer plate and bolt kit and you can use all the 3 series gears. Jim
If you get one from a salvage yard....make sure you get pre-88 model....in 1988 GM went to 30 spline axles and your Skylark has 28 spline axles.