BELT SLAP!!! Anyone else with this problem?

Aloha! 1966 barracuda 273 with a federal power steering pump.

The belt at higher RPM slaps the fan pulley. Leaving a nice wear mark on my newly painted pulley!!!!! GREAT! blaaaaa. :wack: The belt is tight...as a matter of fact I even went and got a smaller belt to see if I could reduce the slap. Still does it.

Anyone ever encounter this? It never did this before until I restored the engine. The only parts that are different is I put a Milodon water pump and it appears the same to be the same setup.

Basically it's a stock configuration.

Mahalo!!!