I just acquired a 1987 Trans AM GTA gauge cluster (not digital) that has the 140 MPH and the 8K tach. I own a 1991 Firebird that has the same physical shape as the cluster I acquired only mine has the 6K tach and 120 MPH speedo. Will these swap out without changing anything? My car was originally a 5.0 LO3. This came out of a 5.7 TPI. I hope they work. I shift well after my redline 6K tach I have now. Any insight is appreciated.