Only thing I would recommend is to not use those lousy rubber caps. I've seen them go bad on the shelf at the auto parts store - the top of the cap rots off. Better to cut a 3" or so piece of heater hose and clamp it to the nipple and find a solid plug for the other end of the hose and clamp the hose around it. A very short piece of 5/8" and 3/4" inch rod work good.
Also agree that there is no harm in blocking them off. If there was a problem, the drivers side of our engines would have self destructed years ago.
