05 silverado 5.3 156,000 miles on it. swapped a tsp high lift stage 2 cam with new ls7 style lifters, 7.4" chromoly push rods, trunnion upgrade, upgraded springs and valve seats, mahle countersunk camshaft retainer plate and other miscellaneous new parts. i however did not touch the oil pump as my thought process was that it was working fine and i didnt want to mess with it and create problems. fast forward to 800 miles later, i was driving home and lost nearly all oil pressure. oil psi dropped to between 0 and 5 psi and would go up to about 10-15 with light acceleration. got it home and swapped out old oil pump and o ring with new gm performance pump and fel pro o ring. fired it up, cold start psi at idle was at 20psi and then as it warmed up it would drop down to around 5psi and the low oil pressure alarm would come on. shut it off, swapped in a melling high volume oil pump and supplied green o ring. idle psi is at 20psi when cold and warm it idles at 10psi with a psi between 20-30 under normal driving conditions and about 40psi WOT. replaced the oil pressure switch, no change. changed oil, didnt notice any metal in it. am now running 10w40 with a quart of lucas. put 600 miles on it and so far have not had any issues with overheating or noises. my question is, how much should i be worried about that psi and besides a camshaft bearing potentially going bad, how likely is it that the new camshaft retainer plate gasket failed?? sorry for the long post and thanks for any input!