[dsraven]

Like the others said. Dont assume its good cause its fresh. Start over like youre seeing the truck for the first time. Check everything and write it down for comparison to specs.get a baseline for reference, timing and vacuum included before you change anything. Use a timing light to check if advance moves as revs increase etc. Try running engine in a dark area or atnight to check for crossfire between ign wires or from coil tower etc. Also, to make sure its not just some water in the carb, remove the air filter and start the engine. Rev the engine up full throttle and at the same time, Using a big rag, cover the carb throat completely for a sec. Not enough to stall the engine, just enough to subject the carb to high vacuum. Thaf can be enough to draw contaminants through the jets if that is the issue. Do it a couple times.then see if the engine runs better. You could have a dirty fuel tank allowing contaminants through to the carb.
Fuel pump pressure and output, before cracking fuel cap, for baseline specs
All fuel and vac lines including tank vent cap
Fuel filter contents
Accel pump output and stream aim. Sgould aim at edge of butterfly valve
Valve adjustment and condition on rockers/shaft. Check oiling of top end as well. Worn shafts and or rockers can affect valve adjustment
Condition of spark plugs and color check
Resistance across points, condition etc. Dwell reading for baseline
Ensure internal connections in distributor are not rubbing ground etc when advance happens and things move
Centrifugal and vac advance check
Condition of rotor, cap and wires
Condition of coil, look for obvious discoloration spots indicating overheating, cracked wire tower or areas around the studs for connections
Check ballast resistor if equipped
Check for good cable connections at battery, engine block, ign switch etc. Wiring is only as good as it's worst connection.
Compression dry and wet

Remember, a lean mixture is harder to ignite so spark will find another path if one is available and that can also change timing. You could start the truck, have someone rev it till it acts up then clamp the rubber fuel line right when it acts up. Shut it off and pull the top off the carb to see how much fuel you have in the bowl. You could also then see if there are contaminants in the bowl as well. Even a bit of water will cause havoc because it wont go through the jets.