Why I'm asking is I'd rather not run line(hose) into
the induction system which puts dirty, oily air, fumes in it. As stated
earlier, trying to avoid dirty ?? going into carb, intake.

The PCV valve is connected below the carburetor so no oily air or fumes are introduced to it. The pcv valve uses vacuum created by the engine sucking air through the intake manifold to suck vapors from the crankcase into the cylinders to be burned with the air/fuel mixture.

David F.
www.firstgens.com

 

Thanks for the response.Have another question. Just learning here, be
patient with what may seem stupid. Have pcv and brake booster lines
"T" together which I'm told is a no no but have had some replies from
others who are doing this. If manifold is sucking vapors from crankcase
why is this bad and could cause booster damage or brake issues. The
fitting is on bottom level of intake(Super Vic), in middle of it. Really do
not want to drill another fitting in the intake but will if this "T" combo
is bad. In case you ask, have no port on carb and no spacer for me
to use. Thanks!

 

The old mopars used a breather with just a hose that went to the air cleaner base. It would fill the air cleaner with oil if the motar had any blowby. Use a breather that a gegular PCV valve fits into.

 

The 'short answer' to why it's a no-no to route the PCV and the brake booster through a common "T" is - that vapors can be pulsed back up into the booster canister during brake cycles causing the vapors to degrade the diaphram and cause early failure.

The fact that the PCV is pulling stuff up the hose to some extent just gets it closer to the booster.
GM actually had some of the problem back in the 70's and retrofitted lots of car and trucks with a small carbon filter (looked like a fuel filter) at the booster to catch any stray vapors that might damage the booster diaphram.
You can still buy the carbon filters at most parts stores in the "HELP" parts items.
If you intend to leave the routing as-is, then at least install a filter to keep vapors out as much as possible.
It's best to use a dedicated tap for the booster on the ear of the manifold and run the PCV into the carb base or front of the intake if possible.

 

Whats the difference between front and back for PVC on intake?

 

The primaries (the 'sucks all the time' side) is on the front of carb where the fitting is.
The system has max vacuum signal to the PCV valve here so it functions correctly.
Installed in the rear the booster can bleed the signal (vacuum) off during brake cycling and cause the PCV to not draw properly.
I've seen oil pooling occur due to this.