i just looked at a z6 head on ebay that was set for $600 and the guy said that the valves were bent from using too thin of a headgasket. is this even possible or is that just his cover for a blown motor.i would never in my life pay 600 for that head but since i read that i need to know if its possible to bend the valves with the engine in time. i need to find out if a z6 head has interference with p29 pistons so when i build my engine i dont risk destroying it. and i do not have a spare head to sit on the block and do a clay check. this stuff would just be good to know.