Aluminum 4 speed gearset conversion question

OD cases have the 308 front bearing and bolt pattern. You can bolt any front bearing retainer except the small one for our cars. There were some early 307 front bearing OD's but I would not count on finding one. Gear sets interchange but you must change everything but synchros. They can have large or small rear splines also. I typically go the other way, swapping OD's into Iron cases so I can swap into std 4 speed bellhousings. That way I can go back if I want to...