I’m having a bit of a challenge sourcing an oil seal for the output shaft on my 3 speed manual transmission (1955 235 engine, Apache 3100). I think I found one on eBay but worry about compatibility.

Anyone have any suggestions? Is there a specific brand and part number that I should search for? An online store (called Summit Racing but they didn’t have)?

Is there a way to find which specific transmission I have? I know which casting numbers to use for the block and head but no clue where to start on the transmission.

Thanks