Nothing against Texas Speed, but BTR seems to be able to get the most out of their cams. My bone stock LS3 with nothing but their Stage 4 cam, new lifters, and headers put out just under 570 crank HP when we factored in a 13% parasitic loss.
Getting 500 crank hp is pretty doable, but 500 rwhp probably isn't going to happen without heads, intake, and a host of other mods.
https://briantooleyracing.com/btr-ca...-33542113.html