howdy; yes; hemis were rated at 425 h/p, but that was at 4500 rpm, and one was tested in about 68 by a "wilcap" co., and it had 423 ish, things were different at 6500 though....... if memory serves, the wilcap test had the h/p on that stocker at about 620ish at 6500+; but the insurancee co's. liked the factorys rating better... JEFF tucson az.