Mine too and it hasn't been rebuilt. Only 77k miles on it (97 1500) Loses
1-½ to 2 quarts in 3000~4000 miles (between oil changes).  No drips on the
floor, no smoke on startup, no smoke on acceleration, not showing up in
the cooling system (thank God), just magically disappearing. It's
obviously burning it, but slow enough not to be visible in the exhaust.
Tailpipe residue, what little there is of it, it is a light grey. This is
also not something new for this truck, it's used oil almost since the
truck was new.

I thought valve guides possibly, but if that were the case it'd blow a
blue cloud at morning startup. And morning starts are clear. Compression
check didn't lend any clues either. Plugs are clean.  I've had some
frustrating history of P0307 misfires for about a year, but the wire
rerouting TSB seems to have addressed that, for the time being anyway.
Knock on wood.

I guess I shouldn't bitch. It's been a good reliable truck and so far has
never stranded me. Chews up front tires if you don't rotate every-other
oil change and piss-poor fuel economy, but not many full-size gas powered
V8 trucks do much better. Sure as hell glad I didn't buy a Chevy or a
Ford.