The tap would not occur in neutral and only at 3,000RPMS in 1st or 2nd gear, no other gears. If was not a "thud" sound but more of a "tap tap tap tap tap" sound. I really cant say what was causing the tap. I am almost wondering if I should just put the car back together and relocate things, delete things, and put new hoses in it. If you guys dont think it could be an internal tap. I really have no clue in saying what caused the tap without looking at the heads....