Mine is a 1980 model, with 1-bbl carb. Well I see 2 holes in the valve cover, 1 in the front (which I know that is where the oil goes), and 1 in the rear. In my rear hole is a PCV valve that goes to a vacuum tree on the intake manifold. In the front hole there is some sort of aftermarket oil cover, with a breather element inside. The top of this cover has a gromet which exposes the element, and is exposed to the outside air.

My question is this, do I need to replace the aftermaket cap with a regular cap, or is it alright that this is exposed to the outside air. If not what do I put in the gromet, and where do I run whatever goes in there to.

 

OT,
On my '68 F100 300 I6 and my '83 F150 300 I6 there was a hose that runs out of the air cleaner assembly (paper or oil bath) and goes into the top of the oil-filler cap, through a plastic L-fitting. But, I've seen these pulled off or lost, the air cleaner hole plugged and an aftermarket oil filler cap installed...with no ill effect. Hope this helps. On my 90 F150 300 I6 the oil filler cap hose feeds over the air filter/intake box and plugs in there. Guess it has something to do with recirculating crankcase or engine gases???

 

OT,
On my '68 F100 300 I6 and my '83 F150 300 I6 there was a hose that runs out of the air cleaner assembly (paper or oil bath) and goes into the top of the oil-filler cap, through a plastic L-fitting. But, I've seen these pulled off or lost, the air cleaner hole plugged and an aftermarket oil filler cap installed...with no ill effect. Hope this helps. On my 90 F150 300 I6 the oil filler cap hose feeds over the air filter/intake box and plugs in there. Guess it has something to do with recirculating crankcase or engine gases???

 

Now that you metion it. My air filter box has that breather filter in it, but it's not hooked up to anything. On my car the breather goes to the pcv valve, and the truck has the pvc valve routed to a vacuum tree. Should I run another pcv valve from my oil cap to the breather, or just leave the cap and breather exposed to the outside air??

 

OT,
I like stock setups, unless performance can be improved by modification. If it were mine, I'd go to a wrecking yard and pull a air filter to oil cap hose assembly from a similar year truck and put it on your truck. No PCV valve though. The stock set up is just a hose that runs from the air filter assembly down to and into the oil cap. Or you could visit the local retail parts store and buy the right size, length hose from them. Probably wouldn't cost much either way.