if it is a rod knock itd likely be a rod bearing just starting to go he's got good oil pressure otherwise. he never specified what pressure was cold at startup tho. Or what pressure he's gettin if he revs it up warm. Could use a stethoscope/hose/screwdriver to get a better listen to where it may be. instead of pulling the boot with a boot puller so you don't get shocked, just ground each plug at a time
rocker/pushrod/valves first then if all clearances are good (buy/borrow/steal a micrometer and a set of feeler gauges you can find clearance numbers anywhere in books or online) make sure your rocker/valvetrain geometry is good to go, even if not the direct source of the knock/tap, will take the easiest part out of the equation (and the parts that could possibly have created a knock in the first place). If still knock, change oil use marvel mystery oil additive or better yet rislone to clean up top end, if using atf don't run it for very long atf will eff up your engine. oil change may also give some clues. its a good idea like other ppl said to take pulleys off accessories and check TC bolts/flexplate, feel fuel pump to see if its knocking before warmed up, could be balancer a lot of other things. If still knock and little oil out of rockers I would then take the intake off and inspect lifters and cam, I don't see how the cam degree could be off or not installed correctly if nothing was changed from the first rebuild. But the lifters/bores could be a problem. then bottom end last (if spark plug test doesnt give good results)
