I want to know the value of my truck
NADAguides, Kelly Blue Book, Edmunds etc can all give you a guide but its really a combination of what you're willing to let it go for and what someone is willing to pay. Start ideal and if you dont get a good response after a few weeks, drop your price until it sells.
Check out other trucks for sale to get an idea of what people are asking but for a 30 year old truck it will all depend on condition, options and originality.
Search Chevrolet C/K 20 Questions
Chevrolet C/K 20 Experts