My 73 240 has triple Webers on it. The previous owner who added these did next to nothing with all of the ventilation hoses coming from the block that used to hook up to the original manifold and carbs. So right now, I have a hose coming out of the front driver's side of the block (under the distributor) that connects to nothing.

Can this hose be blocked or does it need to be vented like the one coming out of the valve cover?

Thanks!

Positive crankcase vent, "You no blockie Joe", should go to a PCV valve in the manifold crossover tube on the SU's. No clue on what to do with the tripples..........

At the very least, it should be vented to atmosphere. It would be better to devise a PCV system on the triples, as others have before (e.g. stonehenge from Zcar).

Install a filter. K&N makes one. Leaving the crankcase open to the atmosphere invites all sorts of air-born trash to enter your oiling system. But do NOT block it off.