The earlier 02-05 crankshafts are widely accepted as the best option for performance applications. They provide the best stability with full counterweighting. They are rumored to be good for 1000hp. Also, in the Competition Eliminator class, where the Vortec 4200 is extremely popular there are guys taking stock crankshafts to 10,200RPM, if my sources are reliable. Basically there method of avoiding the harmonics issues that the crankshaft has is to blow right by it as fast as possible. They usually use torque converters that stall to 7000+ RPM. So they are well past the critical frequency for the entire pass.