M-22 vs. M-21
 

For some strange reason I always thought my '70 455 (3.31 rear) 4-speed was a M-22. Now years after doing the research i can't for the life of me figure out where i saw this. I can only find info to the contrary (M-21 close ratio). Did any '70 cars come w/ the M-22 or are they all M-21s?


The transmission's always been pretty noisy, but now i'm thinking its cause i need to add some fluid...eek!

Aaron

To the best of my knowledge M22 were only available in 71 & 72 .

I agree with gtos, I believe the M-22 was available in Chevys in 1970 and before (back to 1966 I think) but only available in Pontiacs in 71 & 72 behind the 455 HO's.

huh,
 

well what do you know...

Thanks guys

70 455 4 speed m-21's also had a 2.27 first gear,compared to other m21's that had 2.20 first gear.

Wait a minute, scott70. Where did you get this info from??? Reverse had a 2.27:1 and first had a 2.20:1.

I swore i've read it somewhere(i knew reverse is 2.27)but now i think ive been wrong.Sorry for any confusion.

RW is absolutely correct concerning the model years that Pontiac offered the M22 transmission, and it was indeed the ONLY 4-speed available with the 455HO engine in both A-bodies and Firebirds.

However, it was also offered as an option on the 400 4V Formulas and A-bodies as well.

As an example, a friend of mine here in town has a tired but all original '71 Formula 400. M22 with a 3.73 diff. It's obviously a non-A/C car with those gears!

FYI, 1971 and 1972 D-port 455's were offered ONLY with the M40 automatic.