great post, im joining in as im also after this kind of feedback too.

I've got a slightly worked 5l and the aussie 4 speed box (M21) just doesnt cut it, especially on the highway. (running 3.08 rears)

i found the following page useful for ratios in the different toyo boxes:
http://holdenpaedia.oldholden.com/To...ed_gear_ratios

my understanding is that a 'supra' 5 speed could be any of the 'w' series toyota boxes. all in all ya do get an overdrive gear, but the first gear in the toyo boxes would be ridiculous for a v8 from what i can see.

cheers all

Ski man