the effect will be less than a b18c5 (unless the bottom end was a LS, then i'm not sure the outcome) seeing as the c5 is a b18 with a b16 head and a PNP job + other goodies (i think)

you should maul them with an h22 swap in the straight line, the torque will get you to your peak faster, and more effciently then theirs, its on the twistys that they might catch you.