You can also try the customized appraisals provided by such websites as cars.com & edmunds.com. Look for "Black Book ... " & TMV respectively. Edmunds' TMV appraiser requests zip codes so the estimates provided are a bit more accurate. FWIW the "Black Book" values are, from what I've been told by a brother formerly in the biz, heavily relied upon by dealers. Both sites' values may be a bit on the low side compared to NADA or KBB suggested values. At least this was true for the '95 GM trucks I was interested in at the time I was doing my used car research.
You can also try a search for used trucks comparably equipped on sites like car.com, autotrader.com, etc as an additional check.
One thing I've noticed is that 2WD vehicles definitely can be bought cheeeeaaaap compared to 4WDs!
Good luck.