nytrdr24
+1y
you could always try the seafoam trick to quite the lifter...then run the synthetic oil after you get the seafoam out....
generally from what i understand your supposed to break an engine in with mineral oil (non-synthetic), then the first oil change after the break in period swap to the synthetic, ur not really supposed to swap after having put more than the breakin mileage on it....
you only have 15k on it i'd say you'll be alright with swappin to syn, esp if you aren't too woried since your planning on swappin in a 4.3 or w/e....