Sorry but this is a question about my 71 camaro. I just scored a 3.31 12 bolt out of a 68 nova for real cheap($150), but someone installed a small spring perch on it. fortunately its got the right spacing for my car. After I set the rear on the springs. can I use the original bottom plate off my 10 bolt to sandwich the springs? or is there some other bottom plate? Thanks! Jim