I have the Edge Insight which allows me to add a sending unit for temps including engine oil. The filter mount has several plugs but the one I used is pictured below. It can best be accessed through the driver side fender well just behind the upper control arm.
This plug takes a 10mm hex head - do not try to use the closest SAE size because it will only booger up the hex causing you grief.
I highly recommend a 1/2" drive 10mm hex socket, and you'll most likely need a universal too. This plug is also TIGHT. It is installed with Locktite and will put up a fight, so it's important to make sure the hex bit is fully seated.
I have read that you can help break the bond of the Locktite by using a soldering iron on the plug for a while, but I've done two of these now, and brute force along with the proper tools worked just fine.
When the plug is out, you need not worry about losing oil, unless perhaps you just shut the truck off and it's still draining back. This is where things get a little weird. The plug hex is 10mm and GM made the switch to metric along time ago. The plug threads however are good old standard pipe threads. The Edge sending unit is 1/8 pipe thread, and the plug is 1/2 pipe thread, so an adapter is needed
