Bob, You can use a pcv valve to get negative pressure in the crankcase. That's what I use, and it does pull some vacuum. In one valve cover I have my pcv valve and in the other valve cover I have a vacuum break. If you have a
oil dip stick hole, you'll have to fill it with atv. My vacuum break is set at 5 inches, so I'm always running negative pressure in the crankcase. After running the engine, you can pull the pcv valve and the sound is just like opening a can of coffee, pssssss, so I know it's working. Also with running a negative pressure you can use rings with less tension because the negative pressure seals the rings, and less tension is more horses......just my 2 cents for today