With a carbureted engine - should be smelling raw gas if the engine is rolling over without lighting off.
Suggest to find an old spark plug, or to pull one of the plugs, and verify spark.
Fuel, spark, timing - has to be one of those. The challenge is to identify which one. If you've dumped fuel down the carb throat without so much as a 'fart' - spark would be the next thing to chase, IMO.
1989 F150 XLT standard-cab shortbed 4x4, 5.0L, AOD, 3.55 gears, manual hubs, 31x10.50 tires, 218K miles. Repainted Oct09. SOLD - Jan2015
2014 F150 XLT standard-cab shortbed 4x4, 5.0L, 6-speed auto, 3.55 gears, auto hubs, locking diff, trailer pkg, 5K miles.