[leftybass209]

Okay, I did some research.

The hose that goes from the valve cover to the air cleaner spacer, is a flame arrester (Arrestor) spelled either way. The piece that seats in the valve cover grommet, is actually called the arrester from the GM manual.

The manual states, " A flame arrester is installed in the right rocker arm cover on V-8 engines and in hose between rocker arm cover and air cleaner on inline engines".
The baffles however, are to prevent oil consumption to my understanding.

There is slim pickings on what actually fits in that hole. Most everything I've found is a chromed breather. Your options are to find the original grommet, and bend your own metal pipe, leave the original design intact, or add a breather.

Hope that helps.