phils89sc
Registered User
My 89 SC runs very well, has a custom true-dual exhaust with a large Flowmaster muffler/resonator and no mufflers at the back. Headers are stock, piping size is 2.25 or 2.5", cannot remember (except at downtubes). The car only has 87K miles on it and is an auto. Could I safely run a 10% OD pulley? Is my exhaust open enough to allow this?