M20's, etc are 4 speed transmissions usually found in later Camaro's & Chevelle's. Nothing like what you have. The transmission you have uses what is basically an assembly which consists of a "clutch" sleeve with a syncro ring in each end. It is also referred to as a syncro drum. The parts are becoming increasingly harder to find. I have a source in Santa Fe Springs, CA that may have a good used assembly and other parts.
Dave Waugh 562-693-0855.
Just to put it in perspective however, you may spend way more money and time rebuilding that transmission than it is worth.
I got a good trans from another Stovebolt member several years ago to put in a 54 and it's still working fine. Many are upgrading engines and transmissions so there are some out there.
Fred
