Whenever I shift between 2800-3000 rpm as the motor decels this sputtering clanking rattles through my jeep. Sometimes it happens whenever I rev up without the tranny engaged, once again at the same rpms.... does anyone know what this could be, god I hope it's not my valves slapping into my pistons 
did you try revving up with the hood open and see if you can determine if it comes from the engine bay and more specifically from the engine?
if you hear the clanking/rattling throughout the whole Jeep maybe is your exhaust touching something or some lose piece of metal like the heatshield or clutch inspection cover.
won't be your valves touching the pistons as they would bend at that point, but could be some other things if it does come from the engine
