1989 gmc 1500 pick truck will not start?

To keep this simple here some info.I will assume the battery,alternator and starter work fine.Now next are you getting spark at your plugs,to check this pull one plug boot off and turn engine over to see if there is spark.You may have to slide the boot back some to expose the metal end(recommend)so you can verify.Is the carb or if fuel injected do smell fuel in the carb or intake?Now if there is no spark at the plug wire to the plug it could be a bad distributor cap,rotor button,or ignition module possibly the coil itself is bad.If fuel is not present could be dirty fuel filer,and if fuel injected bad injector.I can list more ideas but,the question is somewhat plain and could be any number of problems.For instance 89 b2200 turns over but will not start.That is easier to help clarify the issue.