Assuming that everything you mentioned above checks out ok, you need to start with removing the Distributor Cap, grasp the rotor and rotate it left to right. If you can move the rotor more that 3/16" of an inch (measures at the tip on the rotor) your distributor drive gear and drive gear bushing are worn causing the Crank Position Sensor and Cam Position Sensor (Distributor pickup) signals to be out of sync. If this is the case, the engine will not start and the Bushing and Drive Gear will have to be replaced. Also FYI, Fuel pressure means nothing without checking fuel pump volume. The fuel pumps in these trucks are notorious for failing. Many times a Fuel Pressure Test gauge shows pressure, (Fuel pressure specification is 49.2 psi +/- 5 psi), but when you perform a Fuel Volume test you will find that there is a large volume of compressed air with little or no fuel present. Replace the Fuel Pump Module and inline filters. Other Possible Causes Include but are not limited to: FUEL FILTER/PRESSURE REGULATOR (HIGH PRESSURE); FUEL FILTER/PRESSURE REGULATOR (HIGH); HIGH RESISTANCE IN THE FUEL PUMP GROUND CIRCUIT; DISTRIBUTOR CAP/ROTOR; IGNITION COIL (PRIMARY RESISTANCE OUT OF SPECS); IGNITION COIL (SECONDARY RESISTANCE OUT OF SPECS);
IGNITION COIL DRIVER (PCM); POWERTRAIN FUSES OPEN; SECONDARY INDICATORS PRESENT; ENGINE MECHANICAL PROBLEM; FUEL PUMP RELAY OUTPUT CIRCUIT OPEN; FUSED B+ CIRCUIT TO FUEL PUMP RELAY OPEN/HIGH RESISTANCE; OPEN/HIGH RESISTANCE IN THE ASD RELAY OUTPUT CIRCUIT; OPEN/HIGH RESISTANCE IN THE FUEL PUMP GROUND CIRCUIT; FUEL PUMP INLET STRAINER PLUGGED; NO CKP SENSOR SIGNAL WHEN CRANKING ENGINE; FUEL PUMP MODULE
FUEL PUMP RELAY; KINKED/RESTRICTED FUEL SUPPLY LINE; CKP & CMP SENSORS OUT OF SYNC; NO CMP SENSOR SIGNAL WHEN CRANKING ENGINE; FUEL PUMP MODULE; FUEL PUMP CAPACITY (VOLUME) OUT OF SPECS; FUEL PUMP MODULE INLINE HARNESS.