I need to get some valves for a pair of bare 57 312 G heads.  I see 1.92, 1.94 and 2.020 intakes and 1.60 and 1.625 exhaust valves offered.  Do the oversize valves cause any piston clearance problems?  or...are the slightly oversized valves allow for wear and cleanup of a valve job?

Paul J. - '57 E Code