After not being able to find the leak and speaking with Carbking (thx Jon), I bought a compression tester and checked all cylinders today. Here's what I found. #1 and #2 were 129 pounds, #3-#5 were 120 pounds. #6 was 110 pounds. Also, I looked (again) at the plugs after just a few minutes of run time. #1 and #2 looked fine. #3 and #4 had a fair amount of carbon. #5 and #6 had a lot of carbon. I have a pic of #1 and #6 in Photobucket (link below) showing the difference between the two. Can anyone tell me what these varying compression measurements mean and if that's enough to cause one of my two carbs to have almost no vacuum? Any words of wisdom would be greatly appreciated. I'm about to pull out what little hair I have left. Thanks to all.

http://s42.photobucket.com/user/abbynormal44/library/

Last edited by SmallBlockHead; 03/10/2015 2:08 AM.
1952 Chevy 3100
Semper Fi !