My car was alead set up with front motor plate, 1/2 inch thick, I put a mid plate in also but man I have been cussing that 1/2 inch front one, it needs to be 3/8ths.
If it is belt alignment that is the problem, have the water pump housing milled. I have a 1/4" Barton plate, and I just took .250" off the pump housing. The alternator bolts right to the plate, belt lines up fine. It did on the last one too.