Funny, Bucky is it's nick-name.
Carb- The main fuel tank was replaced, with a brand new tank. There is a pre-filter on the carb, and they originally checked for something similar but found nothing. I used some Seafoam carb cleaner in the tank just incase. I might need to have the carb rebuilt again, just to make sure.
Ignition- We reused the harness from the original truck, it was in good shape, all the wires were still flexible, no cracking and connections were good. I have a question about the coil, when I bought the truck the coil is sitting on top of the engine, and when rebuilt, they placed it back there. I've always wondered if the coil could overheat with the engine and not work properly.
I'm not with mechanics, however, is the Duraspark an electronic ignition? Also, do you think there could be something with the vacuum between the distributor and the carburetor?
I was looking at the 1968 service manual I have and it says the following under "Misses erratically at all Speeds". Ignition System, High tension leakiage acroos the coil, otor or distributor cap. Defective ignition switch. Excessive distributor cam runout.
Any of those ring a bell?