Does anyone know what these parts are called?

[tucsonjwt]

So, that would be called a crankcase vent tube and/or crankcase vent hose. The idea is for fumes from the engine to be taken into the carburetor and burnt up - works with the PCV valve on the other side of the engine for ventilation and emissions control.
Can you post Year, Make, Model, engine, transmission here? That is the first step to find your vent hose/tube part number. Caution: a stock OEM crankcase vent hose cost me $43 for my 454 from Vintage parts - the only place that had one. 350 engine should be cheaper and more readily available.

[Scott26]

thanks its a 86 gmc 1500 with the 5.7 350 with a th700R4

[tucsonjwt]

I can't find parts online from the usual sources. You should contact your local GM dealer to get the correct GM part numbers, then research those numbers on Google.
Can you post of pic of the area in question? You should need a rubber grommet for the valve cover (likely available as a Dorman aftermarket part), a connector which goes into the hole in the grommet ( I get p/n 3942528 for a G van 1986 - don't know if this is correct for your truck - $21.72 + S&H from Vintage Parts - vpartsinc.com), plus a rubber vent hose. The vent hose can be a length of rubber emissions hose of the correct size, but if you have a sharp, close bend then the hose will pinch and cut off air flow - that's why I needed a factory pre-bent short hose.

[TheWhiteElephant]

Originally Posted by tucsonjwt

I can't find parts online from the usual sources. You should contact your local GM dealer to get the correct GM part numbers, then research those numbers on Google.
Can you post of pic of the area in question? You should need a rubber grommet for the valve cover (likely available as a Dorman aftermarket part), a connector which goes into the hole in the grommet ( I get p/n 3942528 for a G van 1986 - don't know if this is correct for your truck - $21.72 + S&H from Vintage Parts - vpartsinc.com), plus a rubber vent hose. The vent hose can be a length of rubber emissions hose of the correct size, but if you have a sharp, close bend then the hose will pinch and cut off air flow - that's why I needed a factory pre-bent short hose.

Wouldn't it just be much easier to put a breather like this on the passenger side valve cover and eliminate the hose on that valve cover altogether? Only issue I'd see is if you are running an OEM air cleaner lid, which it sounds like you are. I'm getting an open element cleaner on mine and putting a breather like the one below on the passenger side.

[tucsonjwt]

Originally Posted by TheWhiteElephant

Wouldn't it just be much easier to put a breather like this on the passenger side valve cover and eliminate the hose on that valve cover altogether? Only issue I'd see is if you are running an OEM air cleaner lid, which it sounds like you are. I'm getting an open element cleaner on mine and putting a breather like the one below on the passenger side.

Only if you don't have to pass emissions
Would you have to replace that paper filter breather over time?