The original PCV setup that came from Chevrolet, mostly on big trucks, is shown in the pictures (1954/55 261). Follow the path through the air cleaner, valve cover, engine and out the draft tube. From there through the PC valve, metal tube (not a hose) then into the intake.
A later version (California System?) removes the draft tube and replaces with a plug. The hose that went to the draft tube is now connected to the opposite end of the valve cover. The path is now air cleaner, valve cover, PC valve then intake. Which system is best? Both remove blow-by gasses. If you live in California you had/have to follow the state requirements.
Since you have a 1962 engine in a 1951 truck, originality is probably not a major concern. Looking at your pictures, I noticed that the threaded PC valve is missing on the road draft tube, the valve cover has a chrome (vented?) oil fill and an elbow that looks like the one from a AC PCV kit or original GM mounted on the valve cover. If it was my truck, I would change out the oil fill to one that's not vented and has a new gasket to seal good. Make sure the elbow on the valve has a good rubber seal (air tight). Since the original PCV with threaded connection (AC CV469, CV208 and CV965) are hard to find or $$$ you'll need a CV609 which has hose connections. You'll need to work out the fittings. I would stay with the original size of hose (5/8") so it doesn't affect flow. You'll need a 5/8" hose from valve cover connection to you air cleaner (which is not shown in your pictures).
If you don't want a PVC system then connect the hose from the road draft tube to the valve cover elbow. Use a vented oil fill. You don't need a connection to the air cleaner.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
