Hmmm interesting... It certainly makes sense to pre-fill if possible. One is in upright where the other is horizontal. Both of these vehicles cost less than a good set of heads though.

The oil supplied to the pump makes its way through a full-flow oil filter into a 1/2 inch main gallery on a small block. The main gallery is positioned above the camshaft. The lube travels from there through a hole to the groove situated nearby the rear side of the rear cam bearing. This is the position where the lifters and rear main are oiled. The four front cam bearings have grooves that pass to each individual main bearing. Oil passes down into the crankshafts main journals through tiny holes in the upper main bearings. From the main journals it travels to the rod journals.