Ive got a 68 Roadrunner, its an auto car Im considering changing to a 4 speed...ive got a 71 alum bb bell, is there any reason this wouldnt work in the earlier car? Im not concerened with clutch dia, as ill run whatever works in the bell. also have a 67 small retainer hemi box, I know ill need to swap out the bearing retainer or get a adapter ring...