Hy Josh_53GMC, pull out one of your plugs and crank the engine over with your thumb or finger over the plug hole, just to make sure you have compression, sometimes when engines sit the valves stick in open positions. Another thing to check is to crank the engine over with the distributor cap off, just to make sure that the cam and distributor are turning over, cam gear failures are one of the reasons why these trucks got parked in the first place. I hope that helps.
