PAY A MECHANIC A 100 BUCKS FOR DIAGNOSTIC AND THEN YOU CAN QUITE WASTEING MONEY ON PARTS YOU ALL DO NOT NEED!!!
The shot gun approach which is replacing parts at random in the hopes that you will fix a problem you don't understand does waste money and generally does not fix anything. If the problem is difficult a hundred bucks may not do it.
There still are shops where if you promise to buy the parts from them, they will diagnose it for free. Or buy an elm327 or another free obd tester and should work (some don't eork on can).
I usually just remove the radiator cap and drive a new car under it.
Looking for a Used C/K 1500 in your area?
CarGurus has 806 nationwide C/K 1500 listings starting at $2,600.
Search Chevrolet C/K 1500 Questions
Chevrolet C/K 1500 Experts