capstoneclub

The M20 or the M21 close ratio 4-speed design? Which version was most commonly ordered?

drop top olds

Torque of a BBO would be better suited to the wide ratio I think.

66-3X2 442

My theory is and always will be if all of the M21 trans were thrown in the ocean,the world would be a better place. The M20 wide ratio trans is better suited for everyday driving in these heavy Olds we drive. When was the last time you saw a drag racer take a lower first gear out and put a higher one in? The object of performance is to get a car moving as easy as possible and the best way to achieve that is through gearing. I've never understood the close ration trans,I mean the only advantage is more even gear spacing. It has been my experience through many years of racing 4 speed cars and driving them,the wide ratio is a better choice. This is my opinion and I'm sticking to it.

dmullin

The m20 had a lower torque rating and was not available in the 455 powered car to my knowledge.
Unless you are drag racing the m21 was a better pick anyway. I have had both in my car (70 442) and the m20 didn't survive the sticky tire.