Chevy 1999 3500 stake/dump truck diesel

For sale 1999 chevy 3500 stake/dump truck 6.5 turbo diesel.under 47,000 original miles. Has a few dents, drivers side door needs some work. This truck has been sitting for a year, but starts right up and runs good. Truck will not shift into overdrive, I think it might be the shift sensor. I’m out of the landscape business and would like to sell. No trades.$7,500