[brider]

Please weigh in your opinion:

My truck runs well except for a slightly rough idle.

Jim C.-rebuilt carb roughly 4k miles ago. I told him the condition, smog-wise, of my engine, and he rebuilt from there. I have no reason to suspect the carb, it's been starting and running great (except) from day 1.

New plug wires, cap, points, etc. Dizzy is a non-usa vac-advance in great shape. Stock manifolds.

Vacuum guage reads 22 in Hg at idle, with slight irregular fluttering, up/down 1-2 in. Flutter sort of mimics the idle stumbles. Behaves at it should thru all other driving conditions.

Best source I could find that addressed the minor flutter mentioned valve overlap on high-lift/high-duration racing cams, but their idle readings are around 15-17 in.

So I think my rough idle is valve adjustment. What do the masses think?

[LT]

Have you tried using the vacuum 101 on the technical page? It has a lot of useful information when it comes to reading your vacuum gauge.

Vacuum 101

[colangut]

This is a great page:

http://www.classictruckshop.com/club...ts/vac/uum.htm

"Needle rhythmically drops 1"-7" below normal Leaking combustion chamber or valve; ignition or plug failure effecting one cylinder"

-Stumbaugh