Aluminum 4 speed gearset conversion question

66fs said

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...

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Yup, right on. You can switch gearsets from iron to aluminum or aluminum to iron, but you have to take everything.

Switching the OD parts into an iron case will also strengthen the OD compared to the aluminum case, you won't have to worry so much about wearing out the case around the bearings.

Switching regular 833 gears into an aluminum case would get you a lighter standard 833, but at the sacrifice of longevity compared to the iron case. It'd be stronger than an aluminum cased OD because of the way the shafts are loaded under power, but it wouldn't be as strong as an iron cased standard gear 833. Probably not an issue at all though, even the 833 OD aluminum case transmissions are decently strong, just fine for pretty much any street driving, even behind a big block.