Any updates? I don't have much to say, but I wanted to bump this thread for you. I'm a bit surprised you haven't had more input from those here who are much more knowledgeable than I am! Usually they love to diagnose issues and talk about carburetors!

Regarding your fuel line dripping while disconnected - you have the mechanical fuel pump, correct? The only reason I could think of for dripping is from expansion in the tank as the temperatures fluctuate daily, forcing a small amount out. Not sure if that is actually possible - just a thought.

Actually, thinking about that... have you confirmed good fuel flow? Maybe leaving the line disconnected but fed into a jar/can and turning over the engine a few times? Would be even better if you could have someone else turn the key and you watch the flow. Crazy thought, but if something was wrong with your tank venting system so it couldn't vent, could possibly cause vacuum in the tank and fuel starvation after trying to start a few times. After letting it sit, perhaps the vacuum dissipates slowly on its own which allows you to try again.

I'm just trying to get some noodles to stick to the wall.... I wish you luck!

 

 

Just proofread my post and realized I wrote a book, and probably a worthless book at that! I apologize in advance

Well, it doesn't look like a feedback carb to me - because I don't see a feedback solenoid (see picture below). Granted, my picture below is from the 1981 manual. I do see many additional control features on yours that mine does not have, but it looks like almost all are vacuum controlled (not electrical, as the feedback solenoid would be). The only electrical connection that I see (besides the electric choke assist) is a single-wire control on the backside of your carb. Behind / in-line with what looks like a throttle dashpot. I don't know what it is / does. Do you have cruise control on your truck? Lots of vacuum hoses that I'm not familiar with in your pics




Unfortunately, those other vacuum hoses may have an impact on your starting ability. Have you checked all of these vacuum lines for cracks/breaks or that they are all properly connected? Are any "open" on the ends, or plugged? Any leaks in these systems, or un-metered air getting into the carb, will cause you issues.

The other adjustments on your carb; float level, mixture screws, idle, etc. should be pretty close between most years/models of the 1-barrel YFA. Even if you made the adjustments based on "the wrong" rebuild kit instructions, I wouldn't expect that to cause you such problems.

I don't want to presuppose your knowledge or skill (and I'm also a novice), so don't take offense to any of these suggestions. I'm not sure what you've checked or replaced at this point, so I might be stating the obvious - but if I were in your shoes I would do the following:

A. If you've changed the carb adjustments since rebuilding; change them back to what the rebuild manual said and leave it there. Those adjustments, if all other systems are working, should be just fine to get the truck to start/run. Only do additional carb adjustments after you've confirmed that everything else is properly adjusted (fuel, ignition system, timing, advance, vacuum, etc.)
B. Check fuel flow; cranking the engine and disconnecting the fuel line to the carb and let it run into a jar. If you have weak / no flow, I would work backwards from the carb to see where the restriction or failure might be.
C. Check ignition; fuel disconnected and spark plug removed (but wire still attached), crank engine with plug near the block to check spark. Weak spark? new plugs, wires, cap, rotor, blah blah. I don't much like chasing electrical - so I won't pretend to know how to fix all of that if you find weak spark.
D. Check timing: if you can't get it to start, a timing light might be your only option to check the timing. Make sure that your damper is accurate by finding top-dead-center on the first-cylinder compression stroke and then checking the timing mark on your damper and front cover timing marker. A timing light won't help you if your damper has rotated and the marks are off.
E. Make sure all vacuum hoses are connected or plugged or not leaking. Don't leave anything disconnected or unplugged. Check the vacuum tree under the EGR. Possibly block off EGR valve to rule that system out (temporarily)? You probably don't need all vacuum systems connected and in working order to start the engine. If you know what they are / go to, I would probably start by only connecting the necessary ones, and capping / plugging all other ports on your carb.

Vacuum and electrical will likely be the hardest to rule out, which is why I was suggesting capping as much of the vacuum lines as you can to get it (hopefully) started. After that, you can uncap / reconnect one at a time to see if the engine rpm or behavior changes - which might indicate a leak or faulty system.

Taking shots in the dark, I know. But I always learn from others on this forum, so I'm interested to see you successfully fix your issue.