anyone know how to install a oil preassure gauge?

yes, but first...what kind of gauge is it? Electrical? Mechanical? What Car is it going on?

sorry guys
its reactive mech.

on a 2000 civic SiR

pick up a oil adapter thread with a bspt threading to go in the block. run the oil line from the gauge to one of the Ts. put the oil pressure sender in the other. hook up the 12v and ground and you are done.