valve covers w/holes

[signsbyesa]

im going to run a vacum and was wondering if it's ok to get valve
covers w/holes or should they be no holes for sealed vacum?
thanx for any help :)

[gyrogearloose]

You want to seal the engine as best as you can. No holes or air leaks if possible. A well sealed engine with a vacuum pump will give you a little more power.