Pop the hood look near to left. you should see a vehicle emission control information lable. Here's a golden oldie for that year tk, pull up the floor mat on the pass side and there you will find the factory spec sheet with color, trim, axle, etc. now that would be way sassy to show them that your truck was civilly disobedient from the plant. look at the alt bracket to see if it has a "risen place for a bolt where an air pump might attatch,a crossover tube between the heads in the rear with a largg vacuum check valve on it, fittings on the exhaust headers with crimped tubes. all these are signs of air pump removals for various configurations and bad news 4 you. good luck