Hey everyone, I am new to this thread. I have a 1979 camaro that was handed down to me from my late father. He had it restored and finished it 3 weekend before he passed unexpectedly. This car was bought by my father in 79. My best memory.
I am looking for some ideas. It still has the original rear end and trans. I would like to eventually replace the rear end with a posi. Looking for best options and help on what to get. As far as the transmission it still has the rock crusher, it has been rebuilt but still seems to shift harsh and doesn't shift fast. Appreciate any help and insight on options. Thanks in advance from other camaro enthusiasts!

 

Sorry to hear about your father, that sucks. "Still has the rock crusher". Did he swap that trans into the 79? There was no M22 after 1974.
You have a few options with the rearend. Upgrade the 10 bolt to posi innards, which would be the most economical way, and will easily handle your vintage V8. Or swap in a complete 12 bolt or Ford 9", which will cost quite a bit more.

 

It's has the munsy 4 speed, the tranny it came with, was told they called that the rock crusher too? He did a motor swap, has a crate 350 in it. I will be looking into rear ends a little more as money is saved. Any recommendations on a leaf spring that will give it a little rake but not too much. I bought some shocks and am still searching for a good leaf spring set up.

 

The Muncie M22 was the one called the Rock Crusher, it was the heavy duty model that came available with solid lifter engines.
However, the Borg-Warner T-10 replaced the Muncie transmissions in January of 1974. No more Muncie after that.
The T-10 is what came in your 79 from the factory. To confuse matters, and what makes people think they have a Muncie, is the factory RPO (Regional Production Option) code for your trans was M21, which is not referring to the Muncie 21 model.

 

If the trans was rebuilt, and has very few miles on it, then it may need some miles to break in and shift smoother. I'd also consider draining the trans and replacing the gear lube with a good GL-4 rated 80w-90w lube. Some people use a heavier multi viscosity like 80w-140w, which will make the trans shift stiffer.
You can have your 10 bolt 8.5" rebuilt with a good posi unit, if the gear ratio is already one you like. Could also change ratios at the time of the rebuild. The 8.5" 10 bolt is almost as strong as a 12 bolt, and even closer if it's rebuilt with fine spline axles at the same time. Lots of other options for rearends too, but most will involve either big dollars, or fabrication to add mounts that fit your car.