1999 Chevy truck won't stay running

Hope someone can help. I have a 1999 Chevy truck with a 5.7 engine, 120,000 miles. Ran perfect before but overheated slightly which caused a valve to stick. I removed the heads and had them reworked and reinstalled. No other problems with the engine. However, now it will crank for approx. 1 - 2 seconds and then cut off. The fuel pump runs when the key is turned on. The fuel pressure is @ 63 lbs. when key is switched on and maintains about 59 lbs. once the pump stops running. Pressure remains at about 62 lbs while trying to start and during short time it runs. I have replaced the fuel pressure regulator and even replaced the complete intake off of another known running engine. I have checked all fuses and relays and the truck will still crank and only run about 1-2 seconds and cut off. Any help or advice on what to try or possible problem would be great.