I just replaced the distributor cap and the rotor about couple hours ago. The cap and rotor were look really bad and old, but, now it runs much better and roughness is gone. I might need to replace the fuel filter too. Do I need to put fuel treatment? if so, what do you suggest for this old truck? At the shop they want to charge me $65 to mix a bottle of fuel treatment. I think its too much for just that. Also, some people told me that it might mess up the fuel injector so, I'm not sure if I want to put fuel treatment. btw thanks for your help, you did well.