Hey guys just wondering if any of you have had troubles with the GM 4.8 motor. Dad has one in his '04 sierra and awile back started noticing we were putting more antifreeze in more often then ever until eventually we were putting a pint in every few days. turns out BOTH heads were cracked. decided were just replacing the whole motor. Apperantly this is a common problem with 4.8s and 5.3s. Just wondering if any of you guys have had this problem.