I am debating back and forth about an underdrive crank pulley setup. I have a 2005 GTO with a heads/cam/intake setup and I plan on doing a few HPDE track days at some of the local road courses. I've read to stay away from the SLP/ASP units due to harmonic issues causing broken timing chains. Is the March a better choice since its fluid dampened? Do I just need to pony up for the ATI even if its only going to see the road course a few times a year? Any first hand experience with the march balancer and road racing? Thanks