[trularin]

It doesn't matter which side it is on, well at least not on an engine I am aware of.

You are venting the engine of gasses that slip past the chambers and pressurize the crankcase.

Taking them back in the engine with the PCV system. Another thing, make sure you have a valve that is for you engine.

I disassemled an engine in a vette thinking the rings had gone, and it turned out to be a Ford PCV valve in the cheby. Blew the worst blue smoke when you got on it.

Just my $0.04 worth.