Looking for Known Problems

I am thinking about buying a 2000 1500 club cab 4x4 with the 5.2L.
I want to know what kind of known problems they have and what to look for before I buy it.
Also What kind of MPG's will I look forward to getting?
any other info that might be helpful would be great thanks.

overall, they are great trucks.
I had a 99 1500 4x4 with the 5.9, and I averaged around 12 to 13 MPG.
the known problems that I can think of are;
in stock form, the transmissions don't like larger tires, or towing heavy loads(if you tow, make sure to turn OFF the OD)
the ball joint end of the track bar tends to wear out, and the plenum gasket can blow out which will cause the engine to ping, and use some oil.

the track bar can be checked by having someone turn the steering wheel wile you watch the front end for movement. and to check the plenum gasket, shine a light down the throttle body and look for oil pooling in the intake manifold.

I never had any problems with the transmission in my truck, but I kept it serviced regularly, and alwayse turned off the OD when pulling stuff.
I did however have to replace the plenum gasket, as well as the track bar at around 70K miles.

hope this helps ya out some,
if I think of anything else, I'll let ya know