gm lists the pump at 140 for gasoline

if he gets it done at the dealership, expect probably 70/hr labor rates, and the book time is probably right around 8 hours

dunno if the 97's are different but for 98's disconnect the fill line, and vent at the rear of the tank (hose clamps on the rubber hoses).
The retainer straps attach to the edge of the frame by the driver side doors, they needed some WD-40 for the bolts to turn, the straps also attach to the frame near the center of the vehicle.
At that point, the tank can come down enough to remove the hoses, and electrical connections.
After those are removed, through carefull rocking of the tank, you should be able to work it loose.