68 Valiant dies and runs lumpy, then suddenly runs fine.

Ok, more work:
Found out the vacuum advance nipple on the carb was hardly pulling any vacuum. Switched that to another free nipple and that improved things significantly. However, the first start in the morning is still always really rough. It seems like it misses a beat every few seconds, and then once in gear will nearly die. If I throttle, it dies. If I feather the throttle and get it moving, it will cooperate, but still stumbles a little from a complete stop after that until it gets to operating temp.

Once it warms up, it's good for the rest of the day. It starts on the first crank, and idles and runs pretty smoothly. It doesn't seem to have much power though. Foot on the floor will get me to 50 mph in around 15 seconds, but it sounds healthy doing it.... just no real 'guts'.
The carburetor is ice cold when I start it in the morning until the motor warms up. The intake manifold gets quite a bit of condensation on it, and it smokes heavily for the first 5-10 minutes after I start it for the first time in the morning.

Did a plug read. The little metal arm (electrode?) is really white, but the rest of the plug is pretty black. Looked like it was rich with too hot a plug. Turns out I had Autolite 66's in it, swapped them for the correct 65's. Haven't read it again yet.