I remember talking with Bill Hahn at the SO last year, and he had these same issues with high boost/high power. From what I gathered, anything over 400HP you will want to drill out the head and block for 1/2" head studs, and torque to 100ftlbs. I *think* he uses an O ringed setup and copper gasket. I dont think its really a issue of a "blown" HG, because its rather difficult to blow out a MLS gasket. They just leak under super high cylinder pressures, which technically, is not a blown HG. It's just basically reaching the sealing limit of the HG and the clamping torque applied to it. The standard head studs should not be torqued over 85 ft lbs or so, because they were not designed to handle those torque loads, which is why the upgrade to 1/2" studs. That info came from Bill and ARP, so i like to think they know what they are talking about :)