Transmission Fitment in a 1977 Chevy C6500

[Kateye_Kenzie]

I'm currently working on getting and figuring out the parts for a truck in the shop and I've been spinning around for several days trying to figure this out. So I am asking you guys who might have a few more years and knowledge over me, would a FS4005B transmission fit into a 1977 Chevy C6500? Is that what came stock? I've called just about every dealership and Chevy hotline I know if and no one has an answer for me, they just send me to another hotline... I have the VIN if that would help anyone, and the casting number that's on the current transmission, which I know isn't particularly useful...

If anyone knows ANYTHING about this midsize trucks PLEASE let me know!! I'm losing sleep over this!

[cadillac_al]

I have seen tons of those transmissions but I never knew what ID numbers they had. I always figured they were Muncies and would have an SM number of some kind. They used to be plentiful around here in farm trucks. I'm surprised google can't come up with an answer.

[Kateye_Kenzie]

So am I! Thankfully I have some old coworkers from a Freightliner Dealership who both relocated to a neighboring shop to my new one who know some people who might be able to help (hopefully) The biggest problem I've been having is that they're 13 digit VIN numbers, which fit into no one's systems anymore... So we're gonna have to look through microfiche and hope for the best at this point.