[sloppy_steering]

Hi everyone,
I've got a 68 firebird w/ a 350 in it. She's got a rebuilt Holley 750 and I was wondering. Whats better for performance? Should I continue to run my PCV valve in the valve covers to the manifold vaccum port on the back of the carb. Or should I use an open element breather cap on the valve cover and cap the manifold vaccum port? I don't have any emissions laws to worry about and I want the best performance I can get.
Thanks,
Brian

[sloppy_steering]

Hi everyone,
I've got a 68 firebird w/ a 350 in it. She's got a rebuilt Holley 750 and I was wondering. Whats better for performance? Should I continue to run my PCV valve in the valve covers to the manifold vaccum port on the back of the carb. Or should I use an open element breather cap on the valve cover and cap the manifold vaccum port? I don't have any emissions laws to worry about and I want the best performance I can get.
Thanks,
Brian

[Schurkey]

You will lose ZERO performance with a PCV valve, and you will cut your overall emissions about 80%.

In addition, your oil will stay clean longer, and it will increase bearing life because of less acid/moisture build up in the oil.

The PCV system was the first--and finest--bit of emission control engineering in the automotive world because it is dirt cheap, extremely reliable, and hugely efficient at reducing pollution.

[Goatracer1]

Your engine needs air flow through the crankcase so you should have an inlet(breather) and an outlet (either a pcv valve or a draft tube).

[J_JAMNIK]

I definitely agree with Schurkey! Ever seen rust on the inside of an old engine without a PCV valve?