Oil? We don't need no stinking oil!

[gearboxx70]

Changed my oil in the '67 Burb (aka Typhoid Mary) today. First oil change since I bought it from PO. Before changing the oil, I pulled the dipstick to check the level...about 1/3 of a qt. low. Not bad.
Drained the oil, pulled the filter, plugged the pan, put in new filter, and checked the manuals (both Haynes and Chiltons because I like to have all the info I can). Manuals say 6 qts. for my 292, so I go with 5 til I crank it over for a minute. (The dipstick read just over full, and the filter was still empty.)
Start her up to fill the filter, shut her down, wait a few minutes, and check the dipstick again. Still over the full mark! WTH?!
I poured the old oil from the pan into the empty bottles. Got barely 3 qts. Ummmmm... With what could still be in the filter I already drained into the pan, that's MAX 3.5 qts. Again...WTH?!
I rechecked both manuals...6 qts. So I put in the last qt. figuring it has the wrong dipstick. (Alot can happen in the last 40+ years!)

Onto the gas gauge issue... It reads at 3 o'clock for the last week. After some reading on many other posts here, I'm armed with enough info I can act like I know what I'm doing. Started checking wires and plugs. Plugs are dirty and corroded, so I clean those up and squeeze in a little dialectric grease for good measure. Follow the wires under the floor, and Oooops! The sender + wire isn't connected to the sender. Sigh! Now I just have to decide whether to cut an access hole in the floor or drop the tank.