On the subject of mileage, my super coupe gets way worse than the stang, even with the h/c/i and 24 pounders(coruse the sc has 36ers and all the blot ons and a coustom exhaust) but stang still gets 21 sc gets 18 and in town is like 10 at best, plus you HAVE to run SUPER in any kind of forced induction, a superc motor will not run on 87, if mileage is a factor buy a bone stock 5.0 gear banger, new plugs o2 sensors and and wires and a kn and call it a day