Wiring it up was easy since instructions are included with the gauge. I needed a brass 1/8" NPT T-piece adaptor to mount the sending unit together with the factory oil pressure sender to the side of the oil filter housing. The part no. for the T-piece is T252 (Le Mans Motorsport part no. LMA 056) and it can be bought at:
Vehicle Wiring Products
Unfortunately the gauge sending unit doesn't fit into the side of the T-piece by itself. To solve that problem, I had the 3/8" NPT brass adaptor that came with the gauge welded onto the side port of the T-piece.
At an ambient temp. of 90*F (32*C), the oil temp. is 150*F (65*C) and the coolant temp. is 180*F (82*C) during highway cruising. In stop-go traffic, the oil temp. creeps up to 180*F (82*C) and the coolant temp. creeps up to 210*F (100*C). No worries about this engine overheating!