I posted this some time ago and could never figure out the answer, so I thought I would try again.

1966 F-100 352/3spd. The tag on the engine block says "reman by Ford". Im owner #4. That's all I know about the truck.

Why do my valve covers have 3 holes? They appear to be oem.

 

Are they Ford FE valve covers. If so I have never seen one like that on a vehicle or in my collection. Have you had the passenger side off to look under it at that third hole? These holes would have baffles backing them up and even if added you should be able to tell so.

 

I have never had them off. I know the front 2 holes are factory. The left front hole has a riser the cap slides down on. The right front hole is cutout for the oil cap. I have not looked inside the pcv hole. They sure look like FE covers to me. They have the "wrinkles" in the front sides like all the others I have seen.