[gmack221]

Unfortunatly Im pretty sure I have bad news for you, the antifreeze that got into the motor oil wore the rod bearing(s) and you now have a piston hitting the head (usually #3). Why am I jumping to this conclusion, same thing happened to me, bought a car with a bad head, changed the head and gasket, made it 70 miles before mine started tapping. Sounds kinda like a sewing machine right? Sorry to give you the bad news, I didn't believe my buddy when he said thats what was wrong, I tore it down and found out he was right.

In my case the rod, crank, and rod bearing needed replaced, so I did a complete rebuild and am back on the road again. Its alot of work to verify im right, either you have to pull the head and see the marks on the piston & head, or you have to pull the oil pan, oil pump, and rod bearings.