The ’55 272 engines did have cross-drilled center camshaft journals and by design, the oil to each bank alternates depending upon the position of the camshaft in relation to the bearings.  With the cross-drilled camshafts, only one side of the engine oils at a time.  As Darrel mentions, just rotate the camshaft and see if that gets you some air going thru the oil passageway.

Install the timing chain oil trough before reinstalling the timing gear set.  That was eliminated as a cost cutting measure and definitely helps with timing chain wear assuming the passenger side rocker arm oil tube has not been blocked off.  

Lorena, Texas (South of Waco)

Thanks Darrell & Ted:
I'm 90% sure that getting air in the bottom end from the LH side and no air from the RH side is independent of cam rotation but I will confirm tonight. 

As happens a lot I was wrong. The LH (driver side) blows into the lower end continuously but for each full rotation of the cam it also blows thru the oil filter hole (just about full bore) 4 discreet times. The points where it blows out the filter seem to be equally spaced and seem to cover just a few degrees of rotation. Nothing muted about it when it blows out the oil filter hole.
The RH side doesn't do anything (even to the bottom end) and cam position makes no difference. Tried a half dozen or more full and slow rotations and got nothing. 

Based on your description, it does sound like the center cam bearing is not clocked correctly and only two of the three holes are aligned with the corresponding holes in the block.  There’s also the possibility that the wrong cam bearing set was used as the cross-drilled camshafts require a different cam bearing set than does the center grooved camshafts.

Two potential fixes but both requires some engine disassembly.  One is with the heads off and the camshaft removed to simply take a long drill bit and punch a hole into the cam bearing starting the drill bit from the deck.  I'm not a fan of this one but have seen it done.  The other fix is to remove the cam bearing and re-clock it but that almost requires the rotating assembly to be removed from the block so that the holes can be properly aligned.  The fix I do not want to mention is putting an overhead oiler on the right bank which I have seen done on several rebuilds where the center cam bearing was put into the block incorrectly.  Regardless, this needs to go back to the original engine assembler to be correctly fixed.

Lorena, Texas (South of Waco)

Thank you Ted and everyone else who responded; back to the shop it goes!