You went automatic. ..correct?
but if it's going in a Ford you don't ever have to worry about reaching any transmissions' max torque rating, so that's a non-issue.
Oh, don't mind that, I'm just stirring the pot with that comment.
The rest is valid, though. The T56 is just a 5 speed with an extra OD gear. The Richmond isn't rated for as much torque as a TR6060 (T56 "magnum"), but it really is a non-issue unless you are pushing stupid power (regardless of who makes the powerplant). People have taken the ROD 6 well past its advertised torque rating with no ill-effects.
I'm not saying that the Richmond is "better" than a T56, per-say. I am simply bringing it up as an alternative.
I am on a quest to find out all I can as far as 6 speed options go. So far, the outlook is bleak, at best. The three options I have found that will handle performance based V8 powa are;
T56 (if you actually consider it a 6 speed),
Richmond ROD6,
and Getrag V160/V161.
The Getrag V16x is found in twin turbo Supras and some BMW's, and would definitely do better behind a high revving 302 rather than a 400" 351-based stroker, as its gears are meant to facilitate higher rpm's.
My plan is to have a set and rebuild them as needed. they are affordable to rebuild yourself and it doesn't look insanely complicated... I know I'll blow oneI'll just pull a 4r70 from pull and pay and run the piss out of it till I need to build it. Those are some stout trannys and have o/d