Okay, I know that this is a Chevy question but a number of members have experience with Chevrolet so here goes.... How effective was the PCV oil separator that the small blocks used in the late 50's/early 60's that fit in the lifter galley? Specifically this one.

I do not think it was considered a PCV system back then. Just a baffled road draft tube as I recall. They worked ok until the rings wore out or something broke internally causing excess crankcase pressure. Then they became a huffer. There would be smoke and a oil vapor enough to oil down the underside and stop the rust.

If you know anyone that left one out of their engine you'd know how well that little canister worked. I never left on out, but I know someone that did. There was oil blowing out all over. The reason it was left out was because the intake manifold they used hit the can. The can they put back in was clearanced with a hammer so it could be used.....

PCV should function the same....lifter valley or valve cover....still pulling vapors out of the crankcase

those were used with a "road draft tube".
early style crank case ventilation system.

They work great. You can see the black draft tube coming out under the ignition shielding attached to the intake. The early small block has a shaft in the block behind the distributor that it blots to that vents though that oil baffle. The newer blocks don't have it I believe starting in 66? The other end hooks up and vents to the air cleaner base.

In this picture I had tape on the end of tube.

Some may not see your tape, So Also the tube then hooked up to the air cleaner base. On earlier versions to a road draft tube routed under the car

Thanks to everyone that contributed to this thread. Much appreciated!

Here's a couple more I found of my 65 when I was restoring it. The engine was clean and had over 100,000 miles on it and you can see the separator. Cleaned right up and reused it on new build. The other picture location of the vent tube installed.

Also all 265-283-327 blocks had these. Some years and model Chevy's used a pvc valve that screwed int he back of the carb along with the tube. It wasn't until 69 when the 350 block come out that these disappeared.