[dubs68camaro]

I'm just wondering if the only diff between the 21 and the 20 are just the ratios. Is one stronger than the other? There are times when I wish I had a lower 1st gear. Thanks!

 

[pdq67]

OK,

I think, THINK, mind you, think that the M-20 is probably right at 425 t, the M-21 probably about 450 t and the M-22 somwhere in the neighborhood of 500 t.

And I think I have read where guy's figure the new, Italian geared, Supercased/steel midplate tranny is a schosh over 600 t, BUT I have NO real engineering data to go by..

None of the manufacturers rated them back then from just a t standpoint b/c too much stuff can cause one to blow-up.

Usually we will spin the tires, then slip the clutch, then axles and u-joints/driveshafts start to go and then finally the tranny or the centersection of the rearend... As we load higher and higher t amounts into our old cars b/c of more powerful AND powerful engines...

pdq67

 

[SooperDave]

OK,

I think, THINK, mind you, think that the M-20 is probably right at 425 t, the M-21 probably about 450 t and the M-22 somwhere in the neighborhood of 500 t.

And I think I have read where guy's figure the new, Italian geared, Supercased/steel midplate tranny is a schosh over 600 t, BUT I have NO real engineering data to go by..
pdq67

so, are the m22 w/ new italian gears stronger than the last run of GM? I can get one or the other and the price difference is about 300-400. I was going with the old GM because made in US and also less expensive...

 

[pdq67]

The all-out bells and whistles Supercased Muncie is one good tranny! Get it!!

pdq67

 

[jaguareats]

the italian gears with a supercase with steel middle and heavy duty tail will cost you about 1600 in parts and need a core to grab other parts out of it. the m-22 is better as in just a larger output shaft,m20 and m21 are the same but close or wide ratio. if you need any i can rebuild what you want if you need a rebuilt unit.

 

[pdq67]

The strength in our tranny's is in the low gear ratio as well as the difference's between the M-21 and M-22's teeth.

The higher low gear is, the stronger it is, so this is why the M-21 is stronger by some than the M-20 and it is the shallower angle cut of the teeth between the M-21 and the M-22 that make's the M-22 stronger ever being the same ratio as the M-21.

M-20 = 2.52-later/2.56-early vs the M-21 and M-22 at 2.20 here..

This really show's up w/ the Sag. 4-speeds b/c there are 4 different low gear ratios from like 2.54 all the way to 3.50 which is like an egg!!

pdq67