Now Scott...i don't expect you to hang on every word I've ever written...especially when I've written about 73 bagillion of them over the course of the last 8 years..Yeah Mike I'm glad your abandoning the weldment bell housing, my concern not only maintaining center during fabrication, but also what kind of flex during full torque flogs.
Did something like this but I used a hemi clutch can to a Waukesha in a Oliver tractor. I had the back of the block bolt holes and clutch can CMM'd. Then put it in CAD and made my adapter, I also had to reclock the starter not only rotating the bolt holes but also moved it to align better with the bell housing. Good planning in CAD made for successful installation. I did plot on paper to make certain I was on the right track before cutting metal.
Cant you use the Toyota bell and make a adapter to fit your transmission even if its thick aluminum plate welded on in the back? It almost seems like if you cut both bells in half and welded them together, obviously jig welded to hold centers.
but in just the last reply I stated that the A340 Toyota bell was gonna get bolted to a plate, and another plate will be bolted to the trans,..and the two of them will be welded together.