I bought a 261 that had seen duty in a 56 2-ton. It came with a factory PCV system and has the valve shown in the military TM. There are specs for the strength of the spring and instructions for cleaning in the 62 truck manual I have. The valve sits approximately at the bottom of the valve cover and is horizontal. The tube runs around the front of the head and is plumbed into the manifold along with the brake vacuum and other lines. I did not use the original valve cover as I have a Wayne repro aluminum one.

I used the vented and filtered filler cap for make up air rather than cut a hole in the oil-bath air cleaner. This caused the problem that at 0 vacuum blow-by comes out of the filler cap and gets drawn into the cab if you have a vent window open. Sometimes even if you don't.

Also it draws too much air and I couldn't get the idle below 800 RPM. I checked it with my unisyn and the valve cover sucks as much air at idle as either of the carbs. So I went back to the road draft tube. HRL suggested that I lap-fit the PCV surfaces which I may do when I get through my long list of other projects that must be done before winter. I hesitate to start over again with an experimental project till everything else is done.

1951 3800 1-ton
"Earning its keep from the get-go"
In the DITY Gallery
1962 261 (w/cam, Fenton headers, 2 carbs, MSD ign.), SM420 & Brown-Lipe 6231A 3spd aux. trans, stock axles & brakes. Owned since 1971.