That is great help! I dug out the manual for my '60 Impala (1958, plus '59/'60 addendum), and there are some additional diagrams that seem helpful. Info on the overdrive unit is more plentiful than the transmission itself...probably because the overdrives were more widely used.

I'll probably end up dropping the whole transmission anyway, but I may give the OD swap a try. We'll see if the roller bearings stay in place.

Using the casting numbers and online info, I got a Fel-pro gasket kit today. The fit is fine, but I am unimpressed with how thin the gaskets are...1/128"...the thickness of two sheets of copy paper.

I have an ulterior motive here. I want to learn as much as possible about the internals of the transmission/overdrive mating. I want to eventually do the 4-speed on-the-tree overdrive mod that's popular with the tri-five guys. I've talked to guys who claimed to have done it, and there's one already modified for sale on marketplace.

Thanks!

Last edited by Peggy M; 08/16/2024 4:18 AM.
This is what happens when you live with a house-full of women, the wife and daughters name all the cars:
1960 Impala - "Frankie" (Frank Sinatra)
1961 Apache - " 'Mater Jr." (wrecker)
1965 Corvair Monza Convertible
1967 C20 "Ol' Blue" (hidden in a log cabin for 30 years)
1972 SuperBeetle Convertible - "Juliet"
1976 SuperBeetle Convertible - "Olaf"
1988 Alfa Romeo Spider Veloce - "Romeo"