The factory had an RPO for commercial vehicles that added PCV for vehicles that wouldn't be on the highway for the most part (making the draft tube ineffective), and an optional kit (shown in the drawing for '55). Note in the image how tall the breather is that replaces the draft tube. It was designed to avoid pulling too much oil vapor into the intake system.
But sure, it can be done. Best bet is to keep the baffling of the draft tube in place, and modify for a 6 cylinder PCV valve (occasionally one of the NOS or used factory PCV set ups show up on eBay, but they are rare at this point). The valve cover should be sealed of course, if the engine has one with the breather slots (model year dependent), and a better inlet connection designed. Note the factory mod has a tube running from air cleaner to valve cover added for that.
Hope this helps!
Drdoug . Please explain the need for the tube running from the valve cover to the air cleaner . I have a 261 with a similar pcv but not a tube to the valve cover . I do have a vented breather cap .
John
