I bought the car non-running. The kid that had it before me flooded the engine with antifreeze while trying to put a larger throttle body and egr plate on. After this the engine started tapping.

I believe it has collapsed lifters, so I replaced them. Meanwhile I removed the heads and rebuilt them... regrinding the valve seats, replacing the valve seals, etc... I changed the oil and motor flushed the engine a few times hoping it would remove the remaining antifreeze. After all of this, it is still tapping.

Any suggestions on what to do next?

 

hows the cam look could there be any cracks or a bad bearing.

 

+1 It could also be a washed lobe on the cam

 

If he hydrauliced the engine it could have a cracked piston or rod bearing out.

 

Are you sure the bottom end is good? Did not wash out the main bearings did it? May have a stuck piston ring from the coolant in cylinders. I would do compression check just to be sure. May have to fill cylinder with oil through plug holes to free up.