I am getting ready to put my heads on and have a couple questions.For a 351W out of a lightning,what would the piston tops look like? would they be true flat tops with valve reliefs on the upper half?The reason I ask is i bought this car a while back and the motor was already done new pistons and all.But the pistons dont have any numbers or letters on them like "030" or anything.Just wondering if these are an aftermarket piston or not.Any way to tell?