A quick check is to take one spark plug out of the head and stick your thumb over the hole (unplug the injectors or fuel pump relay) while someone cranks the engine over. If you feel a lot of air then you have good compression and the valve train is working properly. If not then it is most likely a pushrod issue.

 

PS---don't worry about hooking up the water pump and all that other front accessory stuff until you get it figured out. The engine can start and run for a few seconds without that stuff and not hurt anything.

 

Good point. I ran mine for about 23 seconds, without a water pump with no ill effects.