I just read this thread from its beginning. I think that something got confused along the way.
The purpose of the groove in the one camshaft journal OR the cross-drilling of that same cam journal... is to provide a means for oil to get from one particular main bearing to one particular cam journal that because of either the groove in that journal OR the cross drilling of that camshaft journal, the oil will FLOW in volume to get past that camshaft journal and up to the two passageways above that cam journal that lead all the way to each block deck, and then lead through another passageway through each cylinder head that serves to feed the rockerarm shaft on top of each cylinder bank.
Soooo... the debate is which way is the bast way to get the oil to flow past the one camshaft journal and to the rocker arms above. Do you put a groove around the circumferance of the one camshaft journal OR do you cross drill the one camshaft journal?
From what has been reported, for this engine design Ford wasn't sure throughout the entire 1954 through 1964 production, either. They started out using the idea of a cross drilled camshaft journal in '54, turned to the alternative of a concentric groove in (?) '56 (?) and then in later production (?) '63 and '64 (?) went back to the cross drilled camshaft journal for getting the oil past the one cam journal and to the rocker arm shafts on the top of each cylinder head.
The cross drilled camshaft journal was used in the beginning of production in 1954 and at the end of production in 1964. The cross drilled camshaft may have been used for a total of (?) 4 (?) years of y-block Ford production. In between the beginning and ending of production, the grooved camshaft journal was used for some seven years!
Quite possibly, both pathway methods past the one camshaft journal will work adequately for 'normal' engine operation.
PERHAPS for high rpm performance y-block applications... a groove in the camshaft journal OR a groove on the back side of the camshaft bearing (Vern Shumann's 1959 patented bearing design OR Ted Eaton's suggested block machining modification technique) IS the best technique.
For some street application engines either method MAY be totally fine... just like Ford did...
NoShortcuts
a.k.a. Charlie Brown
near Syracuse, New York