I like that intake and run them on the street. No track time and no quarter mile time. We used to have a quarter mile marked off so we would know if changes helped or hurt. A friend dynoed a 2 barrel pistoned 273 with an Isky E-4 cam and the rest of the Commando good parts including that intake. It made 265 hp. I also run Jet Hot coated factory exhaust manifolds with the Commando 2 1/4 single straight thru exhaust.