Recent troubles with another engine learned me that keeping vacuum in the system from the breathervalve thru the pushrodcovers and into the valvecovers is important in order to retract oil out of the covers.
Also i know that the inletvalve covers have both a small hole which is original.
But : why these holes in the inlet tappets? is it original?, it breaks the vacuum between the rodcovers and the camchest,and for draining oil the tappetblocks are provided with holes! It seems in contradiction with the vacuum story,and if not original i think its important to plug them off.