The 69-74 Muncie three speed only had two ratios:
The ‘car’ or “B” ratio: 2.42/1.58/1.00
The ‘truck’ or “A” ratio: 3.03/1.75/1.00
I believe that GM’s designation for this transmission was an SM-330 - but depending on the model year, platform or model, it could have one of several RPO’s.
I have read on occasion that some full sized cars could get the “A” ratio, but to date I have not found anything to confirm this.
My observations suggest that “B” gear set transmissions always had a front bearing retainer with an OD suited for a car bell housing, and a tail shaft for a floor shifter, while “A” gear set transmissions always had a front bearing retainer with an OD suited for a truck bell housing, and a tail shaft with no provisions for a floor shifter.
Saginaw three speeds seem to be another case all together;
I gave up on trying to understand GM’s coding for them, and what gear sets they came with;
in part because I didn’t have a baseline to compare anything against…
__________________
1970 Formula 400
Carousel Red paint on Black standard interior
A no-engine, no-transmission, no-wheel option car.
Quite likely one of few '70 Muncie three speed Formula 400's left.
1991 Grand Am: 14.4 @ 93.7mph (DA corrected) (retired DD, stock appearing)
2009 Cobalt SS: 13.9 @ 103mph (current DD; makes something north of 300hp & 350ft/lbs)
|