About 1,000 miles after a fresh rebuild on an 04 4.0 SOHC My front timing chain snapped. It had been rattling from the very beginning because the included Cloyes tensioners in the timing kit on Rockauto never primed. The morning that it snapped I had installed the Ford OEM tensioner and the rattling was solved. I bought new heads and OEM chains so we’ll see how it goes on round 2.

 

What's a pair of heads cost....new or refurbed?