AJ
i used the PCV valve suggested on the forum and i believe that came from a BCS kit. i got the NAPA version of the same one.
However i did feel i had way too much vacuum in the engine. so i controlled that with a filtered fresh air intake and a small paint gun valve from HF.
a couple of things i read:
1) it is good for an engine to have fresh air vented in to the crankcase. it helps to remove harmful vapors from the oil and blow-by.
2) the amount of vacuum in the crankcase should be about 4-6 inches of water. (about 1/2" of HG)
PCV systems, after the first couple of years, went to a filtered vented system. Maybe to control the vaccum?
Since there is not a PCV valve designed for our cars, i am not sure you will ever find one that gives the proper amount of vacuum. And there are lots of variables. how well is your engine sealed? how much blow-by do you get? Etc. Plus no one on this forum or anywhere i have read on AH cars has said what that vacuum should be. i got the info above from a tech article on a hot rod site.
by adding the vent and controlling the vacuum with the air valve, i could set my vacuum to just under 1" of HG. (i do not have a water gauge) after setting the vacuum, i checked and it does not change at any speed or in higher vacuum situations. it stays consistent at just under 1". i felt that meant the PCV valve was working as it should.
i first used a brass fitting in the vent line to the freash air filter trying to control the vacuum. after drilling it a couple of times to get close to where i wanted, i saw the valve at HF for a couple of bucks and it has worked better. i put a vac gauge on the line and then just adjust the valve.
i pull my vacuum from the valve cover. it runs from there over to an oil catch can and then to the PCV valve and on to the intake manifold. i use the side port at the tappet cover for my air intake. the verticle vent tube from the side cover to the valve cover is still there for looks but it is blocked with a rubber plug. the plug is actually stuck in the metal T at the valve cover. this way i can disconnect the verticle pipe at the top, hook my vac gauge there to recheck my vacuum at any time.
Does it help with oil leaks? i can't really say for sure. i get oil out the bell hole... from my gearbox. i also installed a rear main seal kit when rebuilding the engine. the engine did not have any oil leaks from the front before i started this project. So i ended up making catch pans that fit under the bell hole and the rear of the gearbox to keep oil off the floor.
good thing is i can pull this PCV system back out in a few minutes if i decide it is not worth it at some point.
here is a pic of the vented side and the valve. if you look close in the bottom right of the picture, you can see my filter. it is tucked away behind the brace.
here is a pic from up top. i have a tri-carb so the vac line comes in to the front intake. the PCV valve is behind the valve cover. the hose going to the back carb has a "T" in it. the side to the carb is plugged and the back of the T goes to the oil catch can on the left.