500 hp is pretty low the average 408 making that plus now with TF's. The problem is in this 12 year old thread there's been 5 or so ? 700+ hp engines raced often posted, that's promising but not exactly proof, more examples are needed before the general consensus is these engines are capable of X HP. I remember when people were afraid to make any decent power with cast cranks etc.., it take a bunch of people over time pushing known/perceived limit's.