Okay a worse problem that we had hoped we had solved when the distributor nut was loose and new fuel pump was replaced (yesterday morning). Not sure if this is related to "Hot starting".
Intermittent severe missing or hesitation which dmjlambert reported and fixed when he had his carb sent off to National Carburetor. His posting seemed very similar to my issue I am fighting now. Though he didn't report any "Hot Starting" issues.
This morning we also went from 12 to 16 timing, for the record.
After we finish the work above we did nice early evening/dusk test drive (6:30pm or so). Some good highway speeds, 50~70 with a little bit of 80mph. Then city driving (lots of stops and goes). We stopped at the Kilgore Chevy/GM house since they had a C10 in the showroom (but it seemed a bit frankensteined to me). We left the truck idling for at least 15 minutes while peaking into the showroom. Then the last bit of our drive back to my brother's house was farm roads (no more than 50mph but lots of 30s). So this trip was roughly 50 miles. No problems. Personally I think it was because my brother was in the truck.
This morning as I said a bit ago, we went with a 16 degree timing. I also needed to fix my left turn canceling (silly spring needed adjustment) but that let me get my steering wheel sorted as it was a few teeth off to the right and it was really getting on my nerves LOL
Soooo, I decided okay let me drive home to Austin, 11am I get no more than 8 miles after getting to 60 and I started getting missing or hesitation. This is actually what it was doing to me my first two tries going home yesterday but a lot worse (yesterday). But the common between yesterday and today is it was hot sun barreling down on my hood, where-as last nights perfect drive was no sun dusky cool.
When my brother gets back from a little trip he wants to put back on the Carter Qjet that the previous owner put on (parts store sold him a 78 Chevy Truck carb). He thought it had a flooding problem early on this rebuild and I bought that matching numbers 72 Chevy Carb from uscarburetors. I have yet to send the core back.
To anyone that took the time to read all that rambing - ideas?
Could this also be related to percolating / vapor lock / fuel boiling? The hard fuel lines to really close the the passenger's ram head. Then the hard line gets close to the block too when it comes up from the fuel pump.