OK, so when you turn the key to the start position the starter does engage an causes the engine to rotate, but for some reason it will not start. If that is not right let me know.
On the driver's side of the supercharger there is a black box that has diagnostic on the cover. Where that bolts to the supercharger there is supposed to be a bundle of grounding wires. Do you have that bunch of wires bolted to that diagnostic plug bracket?
If not, you truck will not start. That is the grounding poing for many of the sensor and such on the engine.