I am considering dumping my 1979 z28 due to severe rust. The car has a 12 bolt out of a '68 or '69 camaro, and I want to switch to a 10 bolt so that I can hang on to the 12. How difficult will it be to switch back to an original 10 bolt? Will I have to mess with the perch springs? Also, what is a rearend like this worth? My neighbor has a '68 rs, and has been bugging me to sell it to him. Thanks again!