the wire cluster coming from the cab on the drivers side should have three wires that connects the gauges for water temp, alternator and oil pressure. All three are one wire connections. The light brown wire is for the single wire oil pressure sender. Dark brown is the alternator signal lead. Green wire goes to a coolant temp sender. The last engine I did, I put a stock sender from the year model vehicle in the oil pressure hole behind the manifold using an adapter available from SummitRacing.com, 14mm x 1/4npt. For water temp I drilled and tapped the waterpump behind the accessory tensioner pulley. The alternator lead is ran straight to the small wire coming from the alternator. If you have a wire going to the pcm already you may be able to cut that lead and tie the dash unit wire to it.