Transmission identity

[Scatterbrain]

Since I just found out my car wasn't an original 4 speed I'm thinking I can put the 4 speed it had up for sale, but I need to know the identity of the tranny.  I found the numbers:

RM8TH9 181635
PR 833 2662 008

but I do not have any way of knowing how to translate.  Anybody know?

[Alaskan_TA]

Some of the numbers you posted do not compute. They can be hard to read, so if possible, can you post a close up photo of the pad?

It appears to be from a 1969 B-Body........

[Scatterbrain]

I managed to snap a photo.  Here it is.

[Carlwalski]

You've read a couple wrong (as far as my eyes can see).

RM8TH9 181635 should be: RM21H9 A 181635 I'm not sure what this means sorry. Looks familiar but Barry would know better.
PR 833 2662 008 = New process A833 4-Speed built on 11/10/1968 and was the 8th trans built. Ps: Looks like there could be a 2 after the 8, so, 82nd trans built that day.

[Alaskan_TA]

RM21H9A is a 1969 Road Runner coupe with a 383 from the Lynch Road plant.

[Scatterbrain]

Guess I have a 69 Road runner 4 speed transmission for sale.  Thanks for the ID.