Just seeing this.
I must have mocked up my transmission 4 or 5 times throughout the coarse of the entire install, checking and rechecking clearances and positions to try to get to the sweetest spot.
I also tack welded the rear mount while in place and supported the case on the crossmember with a wooden shim that allowed me to position the angle in an acceptable range. I also left room for a shim if needed.
When I was done I installed my shortened driveshaft, which I measured for and had shortened after the transmission and mount was all installed, then used that cool tremec tool box app driveline angle finder to confirm it was all good. https://www.tremec.com/menu/tremec-toolbox-app/
Haven't finished my punchlist to drive yet but working on it.