Won't crank....seems as if its not getting spark.

Got fuel pressure
Got Spark
Got injector pulse
Fuses checked
Battery any good-tested it?

sounds like a crank sensor

Check spark plugs, leads, distributor cap & rotor arm, fuel pump, fuel filter, coil pack(s), relays, replace any items that are suspect IE Fuel filter which has probably not been changed since new even though they should be changed on all vehicles every 18 months, all of this can be done at home & will save you a lot of bucks in mechanic/garage fees,

Could be the crank sensor or something in the wiring. Each cylinder has its own coil, so it would be something affecting more than one cyl.
If it won't start at all now, you will have to figure out if it is a lack of fuel to the injectors or lack of spark to the plugs, or something else.
Are you saying the check engine light does not come on when you turn the key on, or just not when it is running rough ?

I doubt running out of gas burned up the pump. A scanner doesnt say anything, it puts out a trouble code, what is the code. do you have spark at the spark plugs? if not check the Crankshaft position sensor. What is the fuel pressure?

Have you checked the fuel pressure? Fuel pumps are a common failure item on those trucks. Pick up a cheap fuel pressure gauge and hook it up to the shrader valve on the fuel rail. With the ignition on and you should have 55-65psi. Even if it's a few psi below spec it could stop the engine from firing.Once you determine the fuel pressure isn't adequate make sure you have a good power and ground at the fuel pump. If that checks out, time for a new fuel pump module. I recommend only replacing it with an AC delco unit, I've heard bad stories about aftermarket replacements.
You could also spray some carb cleaner or starting fluid in the throttle body and crank the engine over. If it runs for a few seconds after spraying starting fluid in you know you have a fuel delivery problem.

The stepping motors in the gauge go bad, but uusually they fail gradually, or just one, The dealer charges $300 to fix, do a search on ebay for CHEVY SILVERADO INSTRUMENT CLUSTER for cheaper repair options. gauges are powered by the pcm, no fuses inbetween, so if it runs ok, problem is in cluster

Fairly common problem with GM vehicles. The sending unit in your tank has a small circuit board that an arm is attached to which moves up and down according to your fuel level. This circuit board and arm are not making good contact. Unfortunately the only good solution is to replace this part.

Have you checked the crank sensor?

When I had a problem with my silverado not starting, I replaced all of the spark plugs with factory plugs and then ran sea foam through it to clean it out.I seemed to work and have not had the problem recently.