Thought I'd provide an update on things... When I last posted I was going to have the vacuum advance rebuilt on for my 622-R Delco-Remy distributor. I have had that done and the guy did a wonderful job (see my website post "Stumbling Along" at
http://restoringcornelius.com/stumbling-along/ for more details).
While fixing the vacuum leak helped immensely, it did not solve the problem. I pulled the fuel line off of the fuel pump to start testing it and noticed... there was only the tiniest dribble of fuel coming out
So I ordered some 3/8" copper/nickel fuel line and replaced everything from the tank to the engine bay (see
http://restoringcornelius.com/new-fuel-line/ for additional info). THAT finally did the trick, and now between the cleaned carburetor, rebuilt distributor/vacuum advance, replacement fuel filter (was replacing those items anyway) and finally the new fuel line, I am happy to report that "Cornelius" is purring smoothly. Managed to get out on a test drive last weekend and had smooth, responsive power uphill and down. The idle is now a steady 850 rpm (feels best there - manual states should be around 800). Very happy.
Posting a pic from the drive - it was a gorgeous fall day here in southern Wisconsin on November 24 - 64 degrees and sunny. Just beautiful.
Too bad I have to put the truck away for the winter soon!