This is pretty easy to do. Purchase a fuel pressure gauge at a supply shop, figure $25-$40 bucks. Make sure it has a push button bleed off valve and drain hose to release pressure. That must drain into an approved gasoline container! The gauge will attach to what's called a Schrader Valve, located on top of the engine, at the rear of the intake manifold, drivers side by the firewall on the high pressure fuel line. The Schrader should have a twist off cap, and is very similar to an over-size tire air valve. Screw the gauge hose onto the valve. You will get some fuel spill as you connect and disconnect the gauge. Once it's secure, turn the key to on but don't start, and listen for the fuel pump to run for 2 seconds. It should build 60 PSI and hold. Start the truck and measure the flow when running, at idle it should be 55-60 PSI. Rev the engine and it should momentarily jump to over 60 PSI. Any readings other than that requires more testing to isolate the problem.