The only way to tell is on a dyno, however, that bottom end (stock LS rods and R/S) I wouldn't really take up that high too many times. It's just not made for it.

Put her on a dyno and see where it stops making power, you can get a baseline done faily cheap.

Im estimating your power stops somewhere around 6800-7200. Just a guess however, I don't know your entire setup.

Get it on a DYNO.