Then we are very much alike.
No, all 454's started out with the single line, 727 pump and mid year changed over to the dual line, 768 pump regardless of horsepower rating. I don't study the 396 cars so I can't comment on them. Someone correct me if I am wrong however as I don't profess to know everything about these cars and could be mistaken.
Interestingly enough, I also have a 2nd week of Jan. Leeds sheet that shows a single line 727 pump so they seems to be bouncing back and forth.
Rick