If you want to build just vented bladder shocks you drill one 1-2mm hole straight up thru the top of the cap into the hole where the bushing sits for mounting in addition to the side bleeder on the cap. Don't do anything with the emulsion bleeder hole where the screw goes, leave it closed. I suppose if you drilled thru the emulsion bleed hole instead of the top it would serve the same purpose, just leave the screw out.