93-95 f-150 lightning also have cast iron gt40 heads.svt claimed that it had 240hp but it was actually closer to 300hp.I dont think 240hp can propell a 4378lb vehicle to a 15.1 in the 1/4 mile. I think you can figure what the quarter mile is with this motor in your mustang by takeing away .1 for every 100lbs.