Advancing 2-3* from a base of 10, I could see.
I don't think the starter would even turn it over if it was at 20-30* base timing.

 

There is nothing worse than finding a thread that describes a problem you have and then no conclusion is ever posted. To that end, I now post my final conclusion: I have none.

I played with the ignition timing some and determined that once again, nothing is wrong. Setting it as a base timing of 12 degrees is about as far as I can go without detonation. I've done some driving with and without trailers, empty I can get up to about 13.5 MPG at an average speed of 70, all highway. Loaded I get from 5 to 10 depending on how heavy the load is. If I wanted to rev the crap out of it, I'm sure it would produce the towing results that I'm looking for, but I would be spending a LOT of time revved up and I would be paying for it at the pump, something I really don't want.

I don't think there is anything wrong with the truck, it runs great, it has reasonable power, but it just won't cut it for me. She's a good truck, and under other circumstances we might have lasted, but I'm afraid our short lived, frustration fraught relationship is coming to an end. I recently ponied up the cash and got a Powerstroke, and soon I'll sell the 460.