balnced or not a cast crank is only as strong as its weakest point. Even if its balanced it has the same tolerances (strength wise) than if its unbalanced only difference is how fast it breaks. LS Cranks are hefty but I wouldnt take one that high 8 at most build for 8500 and get a 2 step or rev limiter. I speak from experience when i say you dont need 9k rpm unless you like building engines ? my .2