dont let those numbers fool you. I asked the TF rep at the NMRA superbowl when they cam out and claimed 375 hp from it with just the heads and intake and NOTHIGN else. I asked if the nubmers were corrected, on a chassis or engine dyno. he had no answers. They are good heads and are one of the better ones out there but I will be waiting a few years (5 or so) to let them get some stuff figured out. Until then SVO heads are the best.