I still don’t see the issue. If a 904 with 4.10’s works behind a built engine with a bigger cam, then this will work also.I read what you posted. It is wrong if you have a cam much bigger than stock.
If you have a stock engine and use this transmission and a 2.76 gear, you'll still have the huge rpm drop but it won't matter as much.
What kind of dude is happy with a stock engine??