The temp gauge was actually working before but I went ahead and swapped it anyways. The oil psi and the voltage were not working at all. Not the volts look good but the oil psi bounces around sometimes looks right and sometimes doesn't. And the temp gauge is definitely off lol.
One method :
Plug it in to the truck, run it for a few seconds, and then go to engine off, key on. This will zero out the gauges, so put all your needles on now pointing to 0. Then start again for a few secs and repeat to check accuracy. Some needles might take a couple tries to get right on 0.
Note:
Do it when the truck is cold and do the temp gauge first, before it warms up from starting it a bunch of times, but give it a minute to settle before you put the needle on.