Did you build the engine? Or install the cam bearings? The bearing on the side that has less oil timing could be clocked slightly off and partially blocking the feed hole.
I didn’t build the engine or install the bearings.
I may not be understanding correctly but if by feed hole you mean the alignment between the block and bearing then I don’t think that would have an effect on the duration or timing but more of an effect on the volume depending on how far off the alignment is and assuming the hole in the block is the restriction up to that point.