Hello, All! So... I just purchased a project C20 and come to find out, it was originally an automatic, but it now has a 4 speed manual in it. I don't know when it was swapped or what trans it is. The clutch is shot and I need to find out what Transmission it is so I can purchase the right Clutch. I think it may be a Munci SM465, but I want to be for sure. Any of you guys able to help figure out what transmission it is? This will be my first pre-nineties GM vehicle and I am Mostly a Mopar Guy, but I always wanted a 70's Pick-up. I picked up this '77 C20 Camper special for $400 running, minimal rust, and only a few dents. Pictures to come!

Thanks in advance!
-Cliff.

 

Since it is not factory, you don't know what was put in there. You will need to take the clutch out to find out exactly what it is.

 

I'd take it to a transmission/clutch shop. I've done that with a friends Ford truck.

 

I found some information here that might help:

Chevrolet Chevy Manual Transmission Identification and Decoding