sbc oil fill tube

Looking to build a 32 ford with a sbc. My engine is a 1978. I want to use old style chevy valve covers without breathers. I will use a old style intake manifold with a oil fill tube. My question is snice its a newer engine will the oil fill tube be enought ventilation for that engine. I dont want to put breathers in these old valve covers.

you`ll can drill the manifold just behind the rear port runners to install a PCV valve to connect to you carb (also install a oil baffle on the underside of the manifold) and just install the breather cap on the tube, this will make it breath easier.