What year Nova or variant 8.5 diff will fit into a 68 Camaro without spring perch modification.

72-75 Nova for a 8.5

Depends on which springs you have. There are different spring perches for the mono and multi leaf springs.

I have multi leaf springs

Then you will need the rear end from a car with multi leaf springs.

i think the 8.5 was only available on cars that had multi leafs- weren't multi's standard after 72 or something?

I have an 8.5 out of something that originally had monoleafs. I was told it was from a 72 Nova, but there weren't too many sent through with monoleafs.

I think the 6 cylinder Novas got 8.5 with mono springs.