The correct hookup would be a street T coming out of the block on the front on the manifold side of the engine. A line with a limiting orfice goes to the filter which should be mounted on the pushrod side of the engine. Another line goes from the street T to the head to oil the rocker arms. The preferred place too draw oil for a pressure gauge is from the oil galley about 6" behind the exhaust pipe. It is an 1/8" pipe plug. If you have a filter without a restricted orfice, you could be losing too much oil through the filter and starving the engine. If you will sign up for this site,
http://www.oldgmctrucks.com/ they have some very good pictures of how oil is routed in the discussion forums.
