If you have a 41 ford flathead I would recommend using superior motoring benefits high mileage treatment, super gas treatment, and fuel injector cleaner. I would also say to use Lucas oil stabilizer. Also if needed you should get a fuel additive that treats seals if the exhaust smokes unless it is a two stroke motor. One last thing you should get some carb cleaner. You can get superior motoring benefits from the dollar tree, and yes it works. Some people are hesitant about stuff like that from the dollar tree, but I have tried them and there brake additives saved me a master cylinder, there octane booster saved me tearing apart the engine, there power steering fluid additives saved me a 250.00 power steering pump, there fuel injector cleaner gets me 4 miles a gallon better, and there high mileage fuel treatment gave my car more pep in it's step.