To add to this, the oil pressure and coolant temperature mechanical gauges remained consistent throughout the MJ years and the same senders are used on both the Renix and HO clusters for these two gauges. The only exception is the oil pressure sensor for the 92 MJs as they had a 2-wire sensor vs. the older single wire sensor. The best way to find the correct sender you need is to come in armed with the factory part number. Most auto parts chain stores have an accurate cross reference for factory-to-aftermarket part numbers. It's better than depending on the counter parts drone and his often flawed database. Factory MJ p/n's are as follows for the temp and oil pressure gauge senders:
56026782, SENDING UNIT, Oil Pressure, 86-91
56026779, SENDING UNIT, Oil Pressure, 92 (2-pin connector)
53005309, SENDING UNIT, Temperature, w/Gauge, 86-91
56027012, SENDING UNIT, Temperature, 92