Can anybody tell me what mods have to be done to a production front cover to fit an on center S2 block. It seems to sit .12" out further from the face of the block where the cam & crank sit on the production block. Or do I have to buy a different cover & where could I get one. Also, my stage 2 heads have titanium exaust valves & what appear to be copper seats. Are these O.K. to use in a turbo motor. Any feedback would be great. Thanks, James.