Lee,standard grease gun hose is 1/8"pipe thread on both ends,same as the filter port. The grease gun hose is stiff enough that you can tighten it to the housing by just turning the opposite end,no need to work in close confines. I used a 1/8" angle valve, the outlet is barbed for 1/4"tubing,cost $4 plus 3 feet tubing @ less than a buck. After you take your sample and shut down the engine hang the hose end from the hood with the valve open and it drains back to the engine,little mess.
Another thing this system allows is easy sampling before your expected oil change,you will know if you can squeeze a few more k miles from the oil.
I never liked the idea of sampling from the dip stick,it's too hard to tell if you might be sucking up sludge from the bottom of the pan. If you have a valve on your pan drain you will also need to run at least a couple quarts out before you can take a good sample,then you have to deal with the oil or go ahead and change it. I feel that the valve on the filter housing trick will provide the easiest most representative sample you can take,some by-pass systems are set up just for this propose with a valve port,but not all of us want/need a by-pass set up.
Shovelhead,here's a link for two FREE oil analysises
http://www.pdma.com/sample.htmDon't let it scare you into thinking you need to be a large industral user,they are very knowledgeable about our Cummins and happy to do the tests.
[This message has been edited by illflem (edited 03-11-2001). ]