My TRW Performance Parts catalogue is dated 1974. Could the same cam have different specs depending on when they were made.
In this catalogue, the TP165 is shown to be the stock mechanical lifter cam for 65 thru 70 396 engines. I would think there would be a note somewhere in this catalogue about 65 and 66 big blocks requiring different rear cam journal machining, but it's not there. Someone is slipping.