I am considering adding a PCV to my y block.  If I use an oil cap with a tube intake can I run a PCV valve inline and to the PCV port on my carb?  I'm running an Edelbrock 1405 on a 272.  Will air be drawn through the road draft tube?  Any comments will be welcome.

Oil fill caps that fit the Y Block don't seal to the tube so my thought is that it is not the best place for a pcv valve since it will probably pull in a lot of outside air, rather than crankcase gases.  Also, the draft tube is intended to draw air through the engine due to a pressure drop caused by ambient air moving past the opening.  This may lead to a situation where there is no or reduced intake airflow for the crankcase.


Lawrenceville, GA

Without a late 60’s Z28, non Ford product, tube with a sealing cap it’s not a good way to go. It does have a threaded fitting for a PCV valve and they are readily available. You would also need a breather on a valve cover which I would do at the rear of one. In my opinion the breather suction side should have a cap with a fitting which goes to inner side of your air cleaner so the air it sucks is filtered. This is the factory way on all vehicles. 
Today Blue Thunder is offering a set of very nice cast aluminum rocker covers which will accept a PVC system without swapping out a valley cover with no fitting. Only a Thunderbird plate would be needed for the block side draft tube. If your engine is in good condition a PCV system is a good idea. 

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Thanks all for your responses.  Can I use a baffled PCV valve grommet and have it in the valley cover?  Then run the PCV valve to the PCV port on my carb?  What PCV valve do you guys recommend.

I've been using baffled grommets in my valve cover.  They work well there and should work well in the valley cover.


Lawrenceville, GA

I have used a PCV grommet in an aftermarket chrome rocker cover that did not have an oil splash device welded in and it worked fine. I believe Moroso 68772 with integral baffles, If that’s the one you are asking about it says it fits all GM PCV valves. It has a 3/4” hole for the valve. I’d guess a mid 70’s 350 SBC, ez to look for on Amazon or any parts store that will bring one out. You will need to decide whether straight or 90*  top fitting. If you search in Amazon for GM PCV valves you will find many both straight and 90* and rubber lines with 3-4 curves and angles you can cut and put tubing in between to make it reach your carb fitting. Normally you don’t need clamps as there is vacuum on the hose to tube if you slide the tubing into the hose an inch.
I would not drill the 1.22” hole in the valley cover if that’s where your planning to put it without removing it. If you do remove it I would make a aluminum or thin steel deflector that went under the Moroso type unit clearing it by 3/8” at least and slanting to drain. I’d pop rivet or machine screw it in with thread locker with RTV sealant. 

56 Vic, B'Ville 200 MPH Club Member, So Cal.

If you do drill a hole for the grommet, use a hole saw which is smaller than the desired diameter and then use a Dremel with a grinding stone or small sanding drums to enlarge it to the desired size.  Also, do not simply make the hole as large as the grommet packaging indicates.  FIt it to the grommet, keeping it as small as possible and as large as necessary.  It would be best to get several different brands of grommet and make the hole fit the smallest well.  That way it will work with all (or most).
Simply making the hole the stated size can result in the hole being too large.  Been there, done that.  If the hole ends up too large, thin strips of electrical tape works ok to take up the extra space.


Lawrenceville, GA