[ImperialCrown]

MoparNorm is correct. A fuel pressure gauge can be Tee-d into the connector at the fuel rail and the pressure monitored after shutting the Nitro down. Make sure that there are no fuel leaks with this set-up before taking your eyes off it. The pressure should slowly bleed down leaving a little residual pressure in the rail. This will help keep the fuel from boiling into vapor inside the hot rail and help at the next start up.
By rolling the key between 'run' and 'off' a couple of times before cranking it over may prime the rail enough to have it start up easier.
If this is intermittant, you can tie the gauge safely out of the way under the hood for observation. The check valve is serviced with the fuel pump assembly.
Normal fuel pressure is 58 psi +/- 5 psi.

 

[ImperialCrown]

The less fuel in the tank, the lighter and easier it will be to move around. Go with ~1/16 tank if you can. It can be supported and balanced on a floor jack and flat piece of wood.
Chock the wheels, set the parking brake and mark and remove the rear driveshaft for more tank working room.
Unbolt the inboard side straps and lower the tank slightly. This should allow you access to the top of the tank, quick-connect fittings and pump retainer nut.
A service manual with pictures and methods would be very helpful.