Had a bad vacuum leak and finally found the source. It is this odd looking piece on the valve cover that appears to be a PCV valve. It had a cap on the end that was split. I removed the cap and the engine smoothed out.

The engine is a 383 stroker with a mild Isky cam, Holley 3310, Hooker super comps. The engine would cut out bad at higher rpms. I removed this cap and alot of it went away, but I think I might have adjusted the timing to far advanced and the carb to compensate before I found this vacuum leak. If I plug the end of the fitting the engine runs very rough, but haa haa it sounds like it's got a bad ass cam in it. I hate to leave this fitting open any thoughts or suggestions?? It sure runs better without the plug on the end of the fitting

http://i16.photobucket.com/albums/b11/Toomanyhobbies/P1140042.jpg

that should be pluged now you have a vac leak.. sounds like your idel mixture is way off if unpluging the pvc gets the car to run smoth also check and reset timing........

I noticed your distributor is hooked up to a timed vacuum port... plug the end on that PCV valve and hook the distributor up to manifold vacuum (on your Holley, its under the front fuel bowl, pass side) and I bet it runs MUCH better.

Thanks Air Adam is that towards the front, kind of sticks out at an angle and is the lowest vacuum port on the carb?

yes toomany,, lower right (passenger) front.

Thanks for the help, looks like I have some tuning to do now. Was thinking of tossing that piece and just put on a cap that has the PCV in it.

Thanks Air Adam is that towards the front, kind of sticks out at an angle and is the lowest vacuum port on the carb?

Yes thats the one. Set your ignition timing before you hook that up, then hook it up and it will idle much smoother and run better I bet.