my brother had a 95 cougar with a 3.8 and only a k&n that ran a 16.89 so with a cougar weighing about 3800 or so because of irs and the mustang being 3300-3400-I personally think you will have some trouble beating him.. I'm sorry but auto zetecs are pretty bad(not knocking zetecs, just the efficiency of the tranny), hell my brother's auto duratech couldn't be my stick zetec, so that says enough right there.
good luck though

Derek Johnson 88 TurboTBird 32psi, t3/t4 bb 50trim, megasquirt, 3 bar map, 50lb inj, roller cam w adj. gear, header, 3" downpipe and full exhaust, gutted intake manifolds, spec stg 3 95SE 3L gone