[dv657172]

I have Hedman headers but not that good of vacuum on DS as you had. Not sure in having them installed 4.5" past collector in the header extension makes a large difference or not. Would be interested in checking how much vacuum they do have at idle and at high RPM but not sure how to downsize breather to a standard vacuum gauge.

Appreciate the offer on the breather. Will keep it in mind. Summit has one for $30 and I need some other stuff so will probably go that route.

[Johnny406]

Not the breather, the check valve on the collector. The breather isn't directional.

[dv657172]

typo on my part, I meant the check valve. Appreciate the offer

[aaronman]

Disconnect the evac system. Rev the engine and feel for blowby at the valve covers. If there is none you have isolated the issue to the evac system. If there is blowby you will need to do what others suggested to determine root cause.

[dv657172]

UPDATE

No blowby at the either valve cover breather hole at idle or 4500 rpm

Did a Leak Down Test for a benchmark and had 4-6% leakage at all cylinders except #4 which was 16% and leaking out carb only (intake valve related I assume, its always something )

However, at idle and 4500 rpm both breathers had no vacuum and in fact were pushing air (exhaust) out of them effectively into the engine

Would appear that the check valve on both sides is not working.

Waiting on Moroso tech dept to provide their opinion on whether placement of the tubes into the header extensions rather than the header collector is an issue or not.

[dv657172]

Issue was the evac system, no vacuum. Individual who installed the tubes in the header extensions did so at only about a 30 degree angle (45 recommended) and more importantly did not install them deep enough in the extension. I also did not have baffled valve covers.

I now have baffles installed, new evac tubes installed and definite vacuum at the breathers. You could even here the suction when removing the breathers.