Welp, I give. I got curious enough to mess with my autometer and stock fuel sender setup again today. Still no luck, third time doing this. My gauge goes from Full, 3/4, to 1/2 tank within about 1.5" of sender travel. The last 1/4 tank to empty is in the last 1" or so. Which is totally unproportional. Fuel about 1" below the sender port, reading 1/4 tank..wonderful