Kelley Blue Book does not cover models made older than 1994. For more info visit Kelley Blue Book.
Check out prices for 1987 Gmc Sierra Classic 1500 Cars for sale from different sellers at cars.smartcarguide.com.
There is no specific price range for classic GMC trucks, since the price depends on negotiations between the buyer and owner. Though, classic GMC trucks, described as built through 1975, command less money than their sister truck, the Chevrolet.
Classic vehicle enthusiasts use an informal score guide to judge the value of a GMC truck. Grading on a scale of one to five:
A car considered a "one" is in excellent condition and is a professional frame-off restoration.
A vehicle graded "two" is in fine condition and it may be an older restoration.
A vehicle graded "three" is in very good condition, and completely original and running.
A "four" is all original and in good running condition.
A rating "five" is in restorable condition. All parts are available, however it needs restoration. It may be in non-running or running condition.
Check out this 2014 GMC Sierra 1500 Denali Crew Cab review notes at AutoWeek.