My brother-in-law has a 2004 Yukon with the 5.3 (I'm assuming it's the LM7). Low oil pressure at times and has heard some ticking from the valve cover area (lifters?). He has basically parked it because he doesn't want to damage it (an LQ4 in the family sadly got damaged from an oil pump going out). I'm assuming the oil pump is going out... if that is the case, is there a certain oil pump brand we should look for? Any other tips? I think family is going to try and help him replace it. Thanks!