Jeff, I believe that MY6 tranny is the GM code for the Mopar designed A-833 new process 4 speed with OD. Used in many Dodge/Chrysler vehicles and late model GM pickups. There is a whole chapter devoted to that transfer in the book "THE CLASSIC CHEVY TRUCK HANDBOOK". See link. I'm planning the same swapout, so please let us know how you make out.
https://www.amazon.com/Classic-Chev...eywords=the+classic+chevy+truck+handbook


Allen
Yeah, well, that's just like, you know , your opinion, man - The Dude

1948 Chevy 3600 - goal Original restoration, Current Stage 1 - Disassembly and getting body in primer
1954 GMC 3100 goal Hot Rod, Current Stage 1 - Get body in primer
1931 Ford Model A 5 window Coupe - Old Skool Hot Rod
1945 Ford 2N Tractor - Runs great
1964 Ford 2000 Tractor - Use it every week
1974 Stingray Corvette