Steele,
on top of the fuel filter, there are two 3/8" holes with plugs in them. Choose the one on the left side of the filter (toward front of engine) . Insert a pipe thread nipple to hose adapter, or to a flex line. Insert a small brass valve, the kind that uses a needle valve in series to the gauge sensor. The valve is needed to filter out the pulsations from the lift pump. Those pulsations will kill a mechanical guage and an electronic sensor too. You only open the valve enough to just barely read the full amount of pressure. Not enough to see any pulsation. I am sure there are some instructions in the archives somewhere. But this is the basic idea.