Should have bought a corvette..

Well the original V12 5l BMW would put out IRO 326BHP (and the V8 4l 286) both more smoothly and probably a lot more usefully than the ~300BHP V8 motown iron.

Goodness knows what the transmission is (but again the original equipment whether manual or automatic is almost certain to have been better.

But perhaps worst of all is what having a heavy iron block (as opposed to an alloy one) will do for the superb handling.

Yes you should have bought a Corvette, fine in a line, and that's about it.

Perhaps it might be better to describe this as Detroit junk with BMW coachwork...