Thats news to me, Mike. I thought they used the one piece ones on '67 covers (2 or 4bbl) because they have the little slot in the valve cover bracket for the holders to snap in to...
View attachment 1715206330View attachment 1715206331
**1st pic Photo credit...Phoenix Specialty Coatings...thx Leanna.
I believe the individual ones were used on '64-'66 covers.