PCV valve problems

[swb85]

Ever since putting the 383 in my truck I've had a head-scratching problem with my idle. What happens is it idles fine until you drive it, lol. Push in the clutch after being on the road for awhile and the idle hangs and won't come down.......as much as 200rpm faster than what I have the idle set at. Sometimes it'll even diesel when shutting it down because it's idling so high. Vacuum leak right? I searched religiously and couldn't find one. Well after 3 months I finally figured out the problem, but am not real sure of the fix---hoping someone can help.
Turns out my PCV valve must be hanging fully open after being exposed to higher vacuum levels seen at cruise. When I come to a stop the ball in the valve stays fully open creating a huge vacuum leak which shoots the idle up way high. I removed the PCV valve for a day and the problem completely disappears---idles perfectly. I want to run a PCV on this motor though, so removing it is not a valid solution. So I replaced the valve with a brand new stock one for an '85 c10 w/350. It's a little better, but is still doing the same thing.

Now the problem I'm facing is I know very little about PCV valves and cannot find much info about them on the web, the monkeys at the parts stores are all clueless, and there's nothing but a part # on all these identical looking valves at the store. I assume I need a valve that has a heavier ball or stiffer spring or something to hold it closer to closed at idle. Can anyone point me in the right direction?