Hey all , Have a 74, 350, small block, 4 bolt main. I put an older Edelbrock 4 barrel manifold and a 70s Quadro-slob on it that I grabbed at a swap meet. It has electronic igniiton. The older alum. manifold has the front oil breather tube and cap which was sealed with a freeze plug. I knocked out the plug and put a Slea-Bay, 10 dollar breather pipe and cap on. I got a set of Cal Custom finned and sealed valve covers. When I ran the engine after putting it back together, within three minutes, it started pushing the the rubber valve cover gaskets out far enough to piss oil into the manifold recesses between the head and maifold (both banks). Anyway, I don't want to drill the covers. I now realize that the breather up front is note enough. What do I do? Drill the manifold in the rear and put a 2nd breather? Why isn't that front tube enough? The damn thing is an inch and a half around. Pork
You will still need a way for the air to circulate thru the engine. PCV are road tube. Something to complete the system.
If the cap in the tube you installed is truly a breather cap, then it must be plugged or maybe the rubber seal that keeps it in the tube needs to be pierced. I had that with some Moroso caps I bought. That should be adequate to keep the pressure out of the block but it might still slobber oil without a PCV, the PCV valve is a one way valve and prevents pressure but helps hold a vacuum in the crankcase.
This problem comes up monthly and has been answered repeatedly so I suggest you do a search and learn about PCV systems, how they work and what is needed for them to work. There is a lot of good info on here but you just happen to be the 857th person to ask. Don't take it personally.
Drill the manifold right in front of the distributor (usually a boss there for a coil mount), tap the new hole for 1/4 NPT, and install a pcv valve for a 66-67 Vette 327. Put a "breather" cap on your oil fill tube and hook the PCV valve to the large vacuum port on the back of your carb. The fresh air will come in from the breather cap and draw thru the lifter valley taking the bad stuff with it. Works very well on my car.
The 74 block does not have the provision for the oil fill tube/breather in the front, and no road draft tube hole in the back so, your set up will not work like the older ones did. You could put a pvc valve behind the carburetor in the intake so that it pulls from the valley.
X2 That's how I set mine up and it works great. I looked thru the PCV valve section at autozone and found one that would fit. Only 4 or 5 bucks iirc.
Dutch54 did better than me, I dropped $23 for a corvette 327 item just so knew it would be sized close to what I needed. That's what I get for going to a Corvette show while I was in the middle of my PCV project!
He used a early style intake so he will have the oil tube for the breather now. You can reverse the stystem also. Use a early vette fill tube (the one with 1/4 npt boss on it) put the pvc valve there and drill the intake for a breather. Just remember **** out one port in the other at opposite ends.
Thank you guys. You rock as usual. I will drill and pipe tape a br*** ****** back by the distributer into the valley, then fit in an in line pvc between two hose ends and run that to the big *** port on the back of my Q-slob. Great info. Lovin' the Hamb. Pork Pork
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