I don't dought it made the power, but OOTB RPM heads? Ummmm, No. They kinda suck OOTB and don't flow anywhere near the 315+ cfm needed to make that kind of power at that rpm for that size engine.
That's a cam with .509 advertised. they would have to have 300cfm at .350 lift to make those kinds of numbers. I don't care who built it or dyno'd it. Put it in a car and run it. Weigh the car. Truth be told.