I use the bench. I heat the engine with a heat gun to 220deg, fire it up and run it a 1/4 to 1/2 throttle for a full 1/2 gallon with out stopping at 220deg (i made a custom 1/2 gallon fuel cell). This establishes a perfect piston sleeve match. Then I put it in the car and start to lean it out and run it. I have never had engines "come to life" as much as they do with other methods compared to this method.