Vacuum leak / bad idle

[Romak]

I just finished doing timing cover gaskets, valve cover, etc. (because of an oil leak) and I still have a bad idle issue going on, my car wants to hunt for idle(especially when cold) but doesn't do it all the time just some times. As well as half boosted brakes. You depress the pedal and it's boosted but not fully it gets firm half way down. This issue seemed to be fixed after the last batch of work I did but came back right away within a day.

Things I've replaced within the last year:

All vacuum hoses
Brake booster (reman/new)
O-ring between master cylinder and booster
Booster check valve and grommet
PCV valve
valve cover gasket and grommets
Idle control valve
Intake boot and plastic 45 fitting in it
All intake manifold gaskets including lower to the block

Seafoamed the car yesterday and still no fix. At least nothing I noticed.

That's all I can think of for now.. seriously guys what can be causing this?
I clearly have a vacuum leak somewhere, Is the entire crank case/valve cover and everything under vacuum pressure while its running? What I'm asking is if I had a leaky gasket somewhere would it cause vacuum leaks? There shouldn't be a leaky gasket I've changed almost all of them besides the head gasket.

ANY incite or info would help greatly!!! I'm stumped

[Romak]

Seriously no one has any ideas?