just wanted to know if there are vin #'s on gts engines...either head or block? im wondering because i am having my second enigne put in (meaning third enigne). i would think not since the motor has been replaced once already and it would make no sense to put it on the block or head for replacement purposes...can someone shed some light on this...plus, im almost 100% positive that an auto gts engine would be the same as an mt gts engine right? just different trannys....right? one more thing, since i may be rebuilding this myself(maybe), is it worth it to go lower comp, sleeved, etc...or would that cost substantially more to rebuild than to just buy an engine and pop it in?