Back in about 1972 I took the original 3 speed/Overdrive out of a 1957 3100 with a fresh 283 and put in a Muncie four gear from a 1969 Camaro. It bolted right up the the V8 bell housing.
FWIW: I was never happy with the combo and soon replaced that M20 or M21 with an SM 420.
I remember now that it was a dog when starting off, especially on a hill, the first gear ratio not being a good match, even though the stock O.D rear axle was 4.11. Can't remember now what size tires I was running on the 15x 7 or 8 "chrome reverse" wheels.
