To properly plumb a fuel-pressure gauge, (and I prefer mechanical by the way---I have never had a negative issue), Ascertain the thread and fitting type at the fuel-filter OUTLET.
Install a TEE into the filter outlet that has 1/8-NPT opening for the gauge plumbing.
Into this TEE, first goes a McMaster-CARR 1/8-NPT male x female stainless ball-valve.
Next, screwed into the ball-valve is a McMaster-CARR 1/8-NPT male x female brass gauge-snubber; get the one that says "for air and other gasses", as it limits the pulsations better than the one for fuel.
Now, plumb your fuel-gauge line into the snubber.
Without the snubber, the needle will flinch with each pulse of the pump, soon wearing out the gauge.
The ball-valve is for shutting OFF the fuel, should the pressure-line ever get damaged.
I always install a ball-valve for all mechanical pressure gauge lines, oil or fuel.
There is such a thing as a safety gauge line that is filled with anti-freeze that is supposed to transmit the pressure reading to the gauge in the cab, but those are notoriously inaccurate and sometimes burst, dumping the anti-freeze into the cab.
If you use good gauge-line and make good connections, you will have no problems; it is diesel, not nitro-glycerine.
If you are afraid of the line in the cab, they make gauge-mounts that mount the gauge onto the cowl, just outside the windshield, and they look pretty cool; the gauge cares not that it is out in the weather; these same gauges live for years exposed to the elements on heavy equipment, farm-tractors, and the like.
You want a gauge "range" that puts your normal pressure in the center of the range; an 0-16-PSI is about right for a stock lift-pump.
