Oil pressure problems in 383 stroker motor?

i have a 350 bored out 60, vortec heads, vortec intake, when i first start my car up it has 50-60 lbs of oil pressure and then as i drive it the pressure falls off to 25-35, when i come to a stop and am sitting still it goes to 0, it makes a knocking/tapping sound at around 2RPMS but stops a little above that and doesn't do it in the lower RPMS under that, when it makes the sound the pressure is in the 25-30 lbs range, i just found out that my intake is cracked from being tightened too tight and antifreeze is coming thru the bolt holes, i just wanted to know if replacing my intake and possibly oil pump would fix this problem, thanks!Oil pressure problems in 383 stroker motor?
oil pump may be fine , make sure that coolant has not contaminated the oil. this will thin it out and cause low press. at low idol. try to redo new intake to spec. torque and change oil %26amp; filter first to see if oil press. returns to normal? if not then you know what is next! good luck!