(Ford 302 V-8, circa 1974.)
Here's a photo of the "spacer" between the carburetor and intake manifold. It's "upside down" showing the path it imposes on the crankcase fumes picked up via a PCV valve in valve cover. The "spacer" piece is 1-1/8 inches in height. I'd like to eliminate that 1-1/8 inch by routing fumes directly into the intake manifold. There is already a threaded hole in the manifold, now plugged with a pipe plug, making it a simple thing to unplug that hole, and route the fumes there, instead of into this "spacer."
Your thoughts?

-=Grant MacLaren=-

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I prefer to distribute the vapors amongst all runners vs one, so to not create a lean condition in one jug and risk burning a piston.

That said, some route that way without incident.

Newer carbs have the pvc port right on them. If your carb is on the way out, its a simple solution.

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You can certainly do that Grant although there is concern about leaning out the cylinder/s on that intake runner. Not sure that it's been proven to be a problem or not though and several, myself included, have a PCV plumbed that way.

Can I ask why you are removing the spacer?

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Because of the engine tilt, aren't the rear most cylinders fairly rich already? Given the choice you should plumb to back.

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"Can I ask why you are removing the spacer?"

I'm trying to make the engine box smaller -- narrower and lower. It's always seemed (to me) to be "too big" for the boat. The "spacer" is 1-1/8 inches high, and employs two thick (@ 1/8" each) gaskets instead of one.

-=Grant=-

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If the "spacer" was phenolic, I thought it might be an insulator to help prevent carburetor boiling or heat soak. But being aluminum, I doubt if it helps much -- if at all. Could it be needed to improve vaporization? I'm not sure where the existing plugged hole enters the manifold circuit -- and would rather not remove manifold to see. If I do the plumbing, I'm quite sure it would be very tight fitting -- no risk of leak.

-=Grant MacLaren=-

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I don't mean to threadjack here, but speaking of PCV valves, I've never paid much attention to mine. Is this a part that should be replaced periodically? I'm at 1100 hours on my engine and I know I haven't done anything and I doubt previous owners did.
Bud

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"Is this a part that should be replaced periodically?" It's my understanding that if you remove the valve, shake it, and hear it rattle, it's good.

There are some good descriptions of its care and function on the web:

A link.

-=Grant MacLaren=-

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On my boat, the "clean air" intake is via the filler cap. And the blowby/oil vapor fumes are introduced via the spacer shown above.

-=Grant MacLaren=-