How much vacuum does it pull if any?

I swapped cam in a 318 pick up 35+ years ago that acted like this.
Turned out to be intake gaskets. Rebuilt the whole truck before I touched the right part.
It will end up being something simple and obvious. .......those are the hardest things to find LOL


70` Cuda`,440 6BBL Jerico,Dana 4.56 Still on 93 Pump Gas
9.87 @ 136/1.31-60ft.`09 Mopar Nationals PASSON PERFORMANCE "Stick-Shift" Champ!
2013 StickShift Challenge Winner@ Mopar Nationals!