of the peeps that oil pressure gauge in there ep where did you tap the block or how did you hook up the oil line?

 

Tee off the stock oil pressure sensor port.
You need a 1/8x28 BSPT Fitting to put in the block. DO NOT use an NPT fitting that you can get at the hardware store. You'll cross thread the block. Mcmaster carr (and others) sell the correct BSPT to NPT adapter fitting so you can use standard fittings. If you're using a Deft, HKS, GReddy, etc... sensor, you can just leave the fittings BSPT, because thats what the sensor screws into.
You need to hook the stock one back up (hence the T fitting) so the light in the dash doesn't go on.