When was the Muncie discontinued and replaced with the T-10 or Saginaw? Once the Muncie was discontinued was the option code still m-20 or m-21.
I'm thinking 74 was the last year for the Muncie?
Ron

I was going to say '74 as well, but I'm not sure though.

1972

I believe it is 1974, I had a 73 formula 400 with one so I know they were still around in 73.

Late 74, early 75 according to most of the Muncie ID sites.

I agree with BillK although I have never seen one in a 1975 car.

There MAY have been some installed in a few 75 model cars, but 74 is CONSIDERED to be the LAST year of Muncie production. IF any Muncies ever got installed into any 75 model cars, I've never seen one, plus all the tranny gurus are not aware of a Muncie in a 75 car.

With that said, 74 was the last year for a Muncie.

I've never heard of a Muncie in a '75 model either. Chevy even started using the Warner Super T-10 (both 2.64 & 2.43 1st) in the '74 Z/28. My '75 Corvette brochure, dated 8/28/74 which I've had since Sept. '75, listed both those ratios for the 4-speeds. That tells me the Borg-Warners were in and the Muncies were out by then.
The few Chevelles built in '74 with the LS4/M21 4-speeds were using the last of the M21 Muncies. Pontiac had been using Borg-Warner M20s since the '71 model year from what I have observed. 1972 was the last year for factory M22 installation. I believe that the 1973 noise standards, combined with the general emancipation of performance engines, led to the dropping of the M22. M21s took over for those applications.