just had the three carbs tunes with timing set at 12 degrees, total advance at 38 degrees at 2600 rpms, new Taylor plug wires, new Champion plugs, new pointless ignition. When I left the shop yesterday the car ran great, when I started it this morning I have noticed a steady surge at idle and cruising. At idle I hear a slight popping out the tail pipes. Does anyone have an idea.

plugs....had the same issue recently with my 340... changed the plugs..it runs great...

yup totally warmed, taken for a 15 mile test run and it ran perfect. Started it this morning and it runs like crap. Called Sumit racing and they said it sounds like a internal vacuum leak?????. I went around and retightened all the nuts and bolts I could find and that changed nothing. If I change plugs what would you suggest.

Do you have the distributor vacumn advance hooked up?

yes but tried it both ways with no effect. just hooked a vacuum gauge to the intake and found I am pulling only 14" of vacuum, way down in the late ign. timing area. Prior to this I was pulling 19"

wonder if your mixture screws backed out??? I had a holley 4bbl once that drove me nuts. I took the screw all the way out dabbed a little silicone on it and never had a problem again.

sure it is not that but what we did yesterday was take the center carb apart and found that little o ring had been sucked out of its slot. Don't rmember what it was for but the carb guy said something about idle. Just talked to him and he thinks that o ring may have missed placed again.

my six pak is brand new...i need to replace the power valve as i had a slight misfire thru the center carb...why plugs???? my personal experience is that champion plugs suck...I had the same issue as this fella... ran lousy at idle and was popping thru the exhaust...i changed my plugs to ac...and the car stopped popping and ran well even with the power valve issue...as I said it worked for ME...