What TC are you running. We are both running 1058s and leave at about 2K RPM, 20 PSI of boost. I run on bald 285/75s on stock rims and Winston (the LB7) is on bald 265/75s - we both run consistant 1.7X 60' times. We both also have Eaton E-lockers up front that we lock. I think if you got it to launch better you would run 12.8X. Have you looked into any drag radials, M&H and M/T both make some 28" tall tires - the M&H will fit stock PYOs while the M/T are 12.5" wide and need a wider rim.