Here is the emissions report information maybe this will hepl you all narrow this down. Also when I start the truck it doesn't seem to fire up sharp and strong like I think it should. It's more like a lazy fire up but it does start after a pump or two of the pedal. The truck has 61, 700 mile origanal miles on it.

15MPH Test
HC ppm Limit 155 Reading 236 Fail
CO% Limit 1.31 Readind 2.74 Fail

25MPH Test
HC ppm Limit 1.51 Reading 219 Fail
CO% Limit 1.68 Reading 2.05 Fail

 

It sounds like either your carb settings are really jacked up, your timing reatarded itself or a burnt exhaust valve. Check your base timing.