Hi all , Looking for some help about my evac. System on my 68 Charger with a Hemi. If I check my evac. System with disconnecting the breathers on the valve covers when engine in idle i not feel any vacuum , i Little Shocked because I feel the opposite , I feel the exhaust gases come out of the breather . Seems the check valve absolutely no work .... any idea ? The crankcase evacuation system is from Allstar and the Tube are welded in already from TTI when I order the HEMI625-218 Headers. The whole exhaust system is a 3“ from TTI with H-pipe and Flowmaster 50 series mufflers . Now I ask my self, what’s the biggest problem and why the check valve not work . Is the Flowmaster 50 series to restrictive muffler? What a muffler are the best non restrictive for using a evac.system? ( I know many people say an evac. System not work with a muffler exhaust , but I see and hear also the opposite ) And is maybe the H-pipe also a Problem for an evac System ? Happy for any help!