Jim911
Step back and take a couple deep breaths.
It still comes down to the basics:
Fuel, Air, Fire, Compression, Timing, Exhaust
You need to accumulate some real time information.
Hook a timing light to any plug. Put the light in the cab or tape it to the cowl and tape the switch on.
Drive the truck until the problem starts and watch the light. If the engine dies but the light is flashing regularly until the engine stops turning, it's not ignition. If the light starts to skip or stops completely before the engine stops turning it is ignition.
Do you have a manual choke? If not connect one temporarily.
When the engine starts to break down, start pulling the choke. If it gets better, it is going lean. If it it gets immediately worse, it has plenty of fuel and you are flooding it with the choke.
Hook up a vacuum gauge and run it into the cab. As soon as the engine starts to act up watch the gauge. The changes in vacuum can diagnose multiple problems. There are trouble shooting guides on line that show pictures for all of the conditions.
Using information to eliminate things is a lot less expensive and more successful then guessing.
There are other on the road tests if these don't find it.
