The 2 inch oil pressure gauge in my 3 hole panel was a short sweep 100psi gauge, and after the engine started to warm, it pretty much sat on zero. I wanted to know what pressure if any I had, so I replaced it with a S-W full sweep 30psi fuel pressure gauge, that reads in 1 pound increments. It works perfect. Very responsive, and you can even tell when the oil is fully warmed up. I"m getting 25psi cold start, and can watch is settle down as it warms up, and I get around 12psi at 2000rpm, and 5psi at 500rpm when the 10w-40 oil is hot.
http://oi63.tinypic.com/28ldidt.jpg
