I've been running my set of M&H's since 2006 (yea, I need a new set) and never run or start below 10 psi. I'm always in a 10 to 12 psi range depending on track prep and temp, and run 1.7 and 1.6 60' times.
regardless of inflation pressure at 135+ mph, I assure you that tire has grown just as big as if you pumped it up to 60psi.I would also love a 25x9, i never overinflate mine and had same cut down the middle on my 26" slicks... I usually start at like 10 cold and adjust it thoughout the day after the slicks are hot... weird
I use the 24's and have never had this issue....