Motor mount shim and pinion angle

If it was me, I would read the existing angles on the transmission and 3rd member and log them. Then I would shim motor both sides equally as required. Then re-read the transmission and 3rd member angles again and if required shim pinion up or down
To original angle readings. But that's just me-----
Ya sounds like a plan I'm at an even angle on my rear and trans now . I put an 8 3/4 in it good thing I didn't weld the perches in solid. In the past I've always had the the pinion 2 degrees down but that's was on the drag cars seems like shimming the mounts would drop the back of the transmission