First time on the forum! I have a 73 orange mustang Mach1 C4 3 speed tranny with a shift kit . I would love to know options to have overdrive still with some pep but I don't need the shift kit. Thoughts?
Welcome! You basically have two options: get a standalone overdrive from Gearvendors or you can replace the C4 with the Ford AOD. The Gearvendors is expensive and the AOD will probably take more labor (exhaust, transmission tunnel, driveshaft modifications) so you have to decide what's best for you!