OEM 4 bbl carb spacers?

I just snagged a new Weiand Action Plus/Street Warrior intake manifold off of ebay for $114.00. They are actually dyno tested to outperform the Edelbrock 2121 Performer intake and unlike the Edelbrock, they have a full width carburetor base mount, to boot.

I plan on converting my '65 Mustang 2bbl Autolite 2100 to a '66 C6ZF B 4100 with all correct jets and boosters.

I have in my possession several OEM 1" open webbed carb spacers. They appear to be of two different types. One has the PCV channels drawing off of the secondary barrel openings. The other has the PCV channels routed up to draw off of the primary barrel openings.

I cannot see exactly why either one would not work but I am sure there was a reason for the differences and as I have both to choose from I would like to pick the correct one.