davidn,
I just watched the video of the first start up. The engine is beautiful and runs smooth as silk. There sure seems like there is lots of vacuum advance though...I don't remember a Stovebolt distributor moving that much or staying advanced for so long. Is your distributor plumbed off of ported vacuum?
I went to the Clifford site and they really push the idea of a water heated manifold and the benefits it will give. I still find it amazing they didn't offer to make your purchase 'right', even if it entailed free shipping back to them so they could seal it and return it.
I heard several years ago that the founder...Clifford Sr passed away and left the company to his son. Maybe Jr. isn't interested in good public relations the way dad might have been.
Anyway, your truck is off to a great start with that pretty engine and frame/running gear! Did I hear thunder in the background while you were shooting the video?
Stuart