I have a 83 mustang with a 78 302 with a 5 speed trans.What damper and flexplate do i need to go to a c4.? May 26, 2022 by Ask ✅ Answers ? Best Answer You need “302” pieces…..28 oz. balance factor. The 1980-and-later “5.0L” stuff is 50 oz. Get the pieces for a ’78 Mustang II w/V8 power……….That would have been a factory 302/C4 install.