I recently bought a rear assembly at a swap meet. It has 342:1 gears with a posi-traction unit. I was told it came from a 73 Nova, but the code on it starts with JV which is a 273:1 1975. All measurements look correct except the spring mounts are about 1 inch deeper than my single leaf spring mounts on my 72 nova. Will it work with my single leaf springs or will I have to change to multi leaf springs or change the spring mounts?
Thanks in advance.

It has multi-leaf spring perches. Probably off of an SS car. You can buy spacers that will allow you to mount it with a mono leaf rear spring. Another solution is to start your car down the path to being an SS by buying multi-leaf rear springs.

Big Dave

Nova used the multi leaf on the V8 cars and he mono leaf on the 6 bangers. Jim I think after 74 they were all multi. Jim

I find very few single(mono) leaf 8.5 10 bolts anymore out there.