Hi. New to this site but was told best place for advice. So I have a 1984 grand prix and switched from a chevy 350 to a pontiac 400 from a 70 grand prix. The trouble I'm having now is the drive shaft. I know u can shorten the shaft but I'm not sure if I'm measuring right. The shaft that came with the 400 is maybe 1 inch to long and I have a nice beefy one from a 69 grand prix that seems to fit but rear u joints r like 1/8 inch to big to fit in straps. Any suggestions would be great! And the transmission is a 400 turbo. Thanks