Selecting power valve method Holley 4160

Update, So I jetted down the primaries from 72 to 66 Stock jet size and engine lost some vacuum and I had to raise the idle a hair. Now for sure there is a WOT hesitation only on WOT no where else, it’s a slight hesitation.

Why would I lose vacuum from a jet swap?

I’ll probably stick the 72s back in and wait until I get some 68 or 70s and try them out! Thanks guys!