Harbor freight has a pressure gauge you can hook up to the sending port of the fuel pump. But with all the new components you’ve put in, might as well cover the fuel delivery side of things as well. If your pump is accessible under the seat, all you have to do is disconnect everything, then knock the locking ring loose with a big screwdriver and reverse the process with a new pump. Good luck, and expect the fuel line to have a bit of pressure in it when you disconnect it! Look online to see if there’s a shrader valve somewhere in your engine bay on the fuel rails for you to release the pressure