That would be possible, but you are looking at an expensive upgrade for minimal gain using the T56/T6060 for an "ultimate" transaxle.
9310 alloy is an EXPENSIVE and difficult to machine material for making gears and shafts from...which drives the price up even further. Sometimes it is possible to spec oneself out of the ballpark in a quest to upgrade just a "little" bit more, with minor increases in performance costing much more than the original improvements. 9310 is the material used in the G-Force upgraded transmissions, it is commonly found in helicopter gearboxes (where failure is not tolerable).
The shaft center-distance is the main limiting factor regarding strength in gear boxes, with gear width being the next limiting factor. 85mm shaft center-distance for the T56/T6060 and 3.5" for the Richmond. 85mm is just under 3 3/8", and 3.5" is just under 89mm. 85mm shaft center-distance also happens to be the same as the Porsche G50 and newer 996/997 gearboxes.
So in reality, you could have a Porsche gearbox be just as "strong" as a T56/T6060-based G-force transmission by replacing those gear & shaft materials with 9310, which just makes those boxes even MORE expensive than they are already...which is not the point of this whole exercise...affordability, availability and serviceability is.
By utilizing the T56/T6060 I am capitalizing on affordability of parts (mass production makes individual pieces cheaper to make), availability of parts (it is the only 6 speed manual transmission used in domestic production performance vehicles), and serviceability of parts (since most local transmissions shops have at least some experience with rebuilding T56/T6060 transmissions). All of this makes it possible to offer builders a gearbox that is AT LEAST as strong as a Porsche box, without the premium price tag. We're talking no more than $5500 for a BRAND NEW T56/T6060-based box, using all new components...versus a $5500+ USED Porsche box, with used components, possibly needing replacements and servicing (all of which is going to cost mucho dinero).
For the amount of performance gain spent on adding G-Force components to my transaxle, you could have a MUCH stronger box using standard off-the-shelf components from Richmond in my "big-dog" transaxle. Different spectrum of the same markets really. T56/T6060-based transaxle for street/light track use...Richmond/QC-based transaxle for full-track/high-power street use. BOTH using STOCK PRODUCTION PARTs, commonly available and serviceable, thus making them AFFORDABLE.
This is a business venture after-all. I want to offer these transaxles to builders at a decent price while still turning a profit. There will be no free upgrades, because ALL upgrades have a cost, and all labor has a cost. What I WILL offer is a great product at a great price point, with great service attached. When these transaxles come to market, I will have a full network of researched and referrable shops to service these boxes in the aftermarket, complete assembly manuals, parts lists for non-propietary pieces (gears, shafts, ring & pinion) and replacement components for all propietary pieces. Just like a full-fledged "big" manufacturer, with complete transparency for the consumer...which is something the "big" manufacturers WILL NOT do.
Here is an idea for you, rather then have a mid range using the t-56 and a high end using the Richmond you could have both using the t-56 and have the “high” end run the g-force version of the t-56 which will handle over 800ft-lb of torque That way the casing between the mid and high would be the same.
G-Force Transmissions and Long Shifters
Or skip both and run a tremec 6060 which off the shelf could handle over 600ft-lb in a 3500lb car, good ratios as well.
