Just replaced fuel truck cranks and will not start

Hi, I'd love to help if I can. Can you be as descriptive as possible about how the truck was running before the new fuel pump and how it's acting now? Does the engine "hit" at all while you're cranking it? If it does, then the problem could be in ignition and not the fuel system. Here are a few basic things you can check:

Can you hear the fuel pump running (not always a good indicator because some are quiet.) Use a helper and listen while being as close to the fuel pump as possible. Turn the ignition fully "on" to the "run" position but don't crank. You can most likely hear the pump prime up the fuel pressure. If you don't hear it after a couple of tries, then There is a fuel pump fuse in the engine control fuse box. Check this. There should also be a relay that needs checking.

Of course check to be sure there is fuel in the tank, if it's extremely low, the new pump may not be able to self-prime. Add a couple of gallons if in doubt.

Try disconnecting the battery for at least 15 mins to reset the computer. They get glitches too.

Is the fuel filter clogged? Check/replace it if in doubt. It's usually good to replace that after servicing a pump anyway.

Beyond those tests, would require more details and probably using a fuel pressure gauge.

Hope this was some help and at least gives you a place to start!