I am currently searching for the correct 4 speed for my Chevelle. It is a 1970 SS 396 convertible, 350 hp with the original motor and rear end. The rear is a 331 12 bolt posi. From what I have gathered so far I need an M20 with case #661 with a 10 spline, 2 groove input shaft and 27 spline output shaft. My car was built 3rd week of March so I am looking for a date code of January to late February?? What side of trans should the speedo be on and what numbers am I looking for for tailshaft case and side cover? Any help out there from you tranny experts? I purchased the car in upper Michigan as well as the motor, which was still sitting in the garage of the gentleman that bought it 10 years ago from the car owner. Anybody in Michigan have my trans??

Don't know about Michigan..... But, this guy will build you any Muncie you want with the right casting numbers and date codes you need. He's collected 4 speeds for many years and has a lot of parts to pick from. He ain't cheap, but he knows how to build Muncie the right way.

http://www.kajunjon.com/Main/

Keep your eyes open for the right date code, I would say right up to the second week of March would be perfect.

Only the case has the date on it. You might paying a little more for the right case and having a good core Muncie rebuilt with that case.

Chances are that it will have a VIN stamped on it from the car it originally came from on it.