will a 68/69 Camaro 12 bolt bolt right into a 70-72 Camaro, or are there clearance issues that I will run into? if it will fit, will I need to have the spring perches relocated?

thanks for the help

Not a bolt-in, perches will have to be moved. '70 perches may be different.

A '68 12-bolt will have the U bolt/nut pinion flange, '69s used the larger strap/cap screw style. The '69 flange is longer; that's why driveshafts were shorter.

A first gen. axle is 60 1/4" overall length and a 2nd gen. is 61". The spring perches (as mentioned) are 42 3/4" center to center on a first gen and 45 3/8" on a 2nd gen.

The first generation 12 bolt rear has a value of ~ $1,500 depending on condition. Sell it and use the funds to buy a good rear for your 2nd gen Camaro.