Back before I knew any better, I had a set of scrap valve covers with a slot cut in the tops above the rocker arm nuts for "running valve adjustment" (AKA WRONG). I really doubt that there will be enough volume from the rocker weep holes to be concerned with but if you want to add an extra layer of protection, glue a valve cover gasket to the head to create an overflow dam.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!