There is a defined range for rpm/ duration. You are operating above and beyond that range. Supercharging or turbocharging helps to stretch that range. It lets you "get away" with things that you can't with a N/A motor. In your case, you're "getting away" with alot. 5000+ lbs and almost in the tens,,,, you're doing good. Treat your engine to a little breathing. Go with at least 230 @050. You will be pleasantly suprised.