I haven't actually used the removeable bar lifters either. The ones that I have looked at in the Isky and Crower catalogs appear to have a slot extended from the primary bore of the bar to its end. I think this would let the bar install at any angle. I'm thinking you would need to tilt the bar far enough to engage the slot and then when dropping both the lifters far enough to their bores the bar would be engaged. Know what I mean?

Back to my earlier comment about exposing the pushrod lifter hole. Is the very momentary exposure at max lift going to lose enough oil (not engine oil pressure) to introduce air and reduce oiling effectiveness to critical areas? Such as rocker bearings, valve ends, roller rocker tips? It's my current thoughts that I could reduce the oiling up top with restrictor pushrods, but no easy way to increase oiling if I the problem is at the lifter. That is why I want to fix the exposed oil hole problem. Too much worry?