Well, I timed it to vacuum today and am making between 17 and 18 pounds at idle. With the carb open it drops to 5 but then climbs back up to around 15. I tuned most of the vacuum bounce from 16 to 18 pounds out with the mixture screw. It is probably closer to 1.5 turns out now. And the vacuum vibrates between 17 and 18 pounds with a drop to 16 once in a while, but it is not a rhythmic drop to 16 it seems random. I will do a compression test when I get back home this weekend. The vacuum advance seems to be working on the carb,. Under acceleration the rod pulls in and the distributor rotates.

Also changed plugs and wires today, that seemed to help as well. The plugs that came in it were fairly new,. But when I pulled one, it was black and sooty with carbon.

Last edited by Drtheo; 08/24/2018 3:10 AM.

1950 GMC 1/2 Ton Long Box
228-Zenith carb- SM420-bendix brakes