supports nothing ...they stopped making muncie gearboxes in 1974 from 70 to 74 they used muncie fine spline with the turbo 400 output (32 spline) ..
then from then on they used the borg warner super t10s 2nd design,..in all the chev powered cars..
as far your saginaws go there tad stronger than your aussie 4speed...the t10 boxes made during the latel 50s 60s were probaly on par with your saginaws..
i don't need to read posts as i come from a drag racing back ground and have used both muncies and super t10s with great success and no there strengths..
and yes i've stripped as many boxes as i care to talk about and know how they tick and there weakness and strengths are..
personally speaking a saginaw doesn't rate let alone a aussie 4speed..
If you don't read the post then don't comment on the post! I think that's fair.
I'm not disagreeing with anything you have stated, nor are you contradicting anything I have said btw! We both agree Aussie 4spds are a piece of plastic. I agree Saginaws are at best marginal behind a small V8. And I think we both agree that. a 1970's ST10 is stronger than a Saginaw but below the best of the original Muncies. Original GM Engineering documentation will state the torque ratings of their boxes. I'm almost certain it will show that the M22 was no longer required once the high output big blocks were finished in the early 70's. The last of the LS6's was 1971. LS5 was around in 1972 but it was a shadow of the L88/ZL1 and LS6. That is why they started using the Borg Warner box, it was probably an economic decision too, Borg Warner box was probably cheaper than building their own.