2007 mack granite wont start

thanks for your help in advance guys. so here's my problem, I rolled a main a few weeks ago and the engine seized. so me and my brother picked up a new block and transferred all the parts onto the new block. turbo, manifolds, fuel lines, fan ,etc. anyways now when we go to fire it up it will runs and revs up for about 3 secs then shut down right away. no malfunction light or anything. when it shut downs it as if it loses fuel and or combustion. cranking it after the shut down sounds like its not getting fuel and or combustion. like the injectors are getting fuel. and if we let it sit for a half an hour and prime it. it will do the same thing again. we have fuel pressure, but it doesn't run long enough to get to what the books says it should be at. thinking fuel pressure regulator?