i bought a 70 darts parts car from some hillbillies a few years ago. they had late 70's truck manifolds on it and the drivers hit. power steering box maybe? (cant remember) their remedy was some linoleum stacked up like washer under the motor mount
I think I understand now...I was thinking about the motor mount as in the round poly bushing that the center bolt runs through, but now I think you mean the actual metal mount bolted to the frame, right? Shimming underneath that part? That makes sense, I think. Would I have to smim both sides equally to avoid some other issues, or just the driver's side a bit?
This, of course, only applies if I get headers with fitment problems.