Off the test port or tee off the oil pressure switch. The oil pressure switch is just that, a switch that makes the stock gauge site a mid range when the oil pressure reaches 5 to 7 psi. See page 56 (click here) of the 6.0L bible.
Sorry, you lost me on the ability to follow directions part. Way too many optional items. I'll just retreat now to the garage with my 6ea 12oz beverages. :cowboy: