I have a 99 2500 5.7 vortec did intake gaskets pulled distributer and reset timing several times so i know its gotta be right but Will Not start.. Sounds as if its out of time still.. Barely starts with carb spray but stalls out and spits out throttle body.. Has new everthing ignition wise

 

How did you reset the timing? In the future mark where the rotor is and install back into the same position without moving the engine. This is the easiest way.