7.4 Vortec RPM Surge at Idle

[WarHawk919]

Hey there...
I have a 96 3500 7.4
RPM surge at 180° and doesn't stop unless PCV is pulled out of valve cover.
I have put all new vac line's.
Cleaned MAS
New IAC
New TPS

What else should I look for?

 

[Dud1f3r]

Sounds almost like it's not getting enough air. How's the air filter?