Identifying Saginaw 4-speed or a Muncie 4-speed on a 1967

Q: Identifying Saginaw 4-speed or a Muncie 4-speed on a 1967

How can one tell *FOR SURE* if you have a Saginaw 4-speed or a Muncie 4-speed. How about if its a M21 close vs m22 wide ratio? I read somewhere that all 1967 4speed birds were saginaw-equipped (something about deloean and co having very little time to get the 1967 model out the door?) Did some 68’s also have saginaws?

A: They both have 7 bolts on the cover. The reverse lever on the Muncie is mounted IN the extension housing, where the Saginaw reverse lever is mounted in the side cover.

The M-22 close ratio transmission is easily identified INTERNALLY from the M-20 and the M-21 versions by the angle of the gear teeth. The M-22 was only produced in a close ratio version, so it will not appear on models with high rear axle ratios (3.55 or lower numerically) unless someone has changed it out. The “rock crusher” came in 70-73 years but was also in 1967 vettes. The M-22 differs from the 21 and 20 in the input shaft, cluster gear, first, second, third and reverse idler gear.

Can’t speak to the Saginaw Firebird 1967 vs. 1968 theory. I would imagine there was a mixture depending on engine type or more importantly axle ratio. Check your two digit axle code.

A: V-8s used Muncies,OHC-6 1 and 4 bbl used saginaws but a few 4bbl OHC had muncies ( assembly line goof ups), Easy way to tell apart is muncies are alum. and saginaws cast iron. Also muncies have the reverse lever in the tailshaft. No M-22 were installed in early Firebirds. First gear is 2.20 in a M-21 or 22

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