im looking into getting a 4 guage pillar. i already have a recon that monitors boost and egts. although i think im goin to go with a mechanical boost guage, oil pressure, water temp, and i need one more to fill the 4th spot any suggestions? i was thinkin maybe oil temp? alos what degree range do i need for the water and what pressure for the oil? i have put these kind of gauges on gas trucks but im just not sure about a diesel motor if the pressure and temp ranges are different.