boost fed ls

I started my install yester and everything was going good intil we went to bolt the manifold up, we had to grind the **** out of the bolck. I mean most of the upper webing, most of a tab that is located below the engine code, and the part were the serial and engine code is stamped on. Any one have this problem, the only thing we can think of is that when we checked the turbo they sent me a 60trim and a 63 ar housing, i ordered a 57 trim and a 63ar housing. coulkd this be my problem?