15.1. Only Hoosier LM 11 x 88”, 90” or 92” M20 or M40 are permitted after the expiration of the predetermined grace period. Prior to the implementation of the revised tire rule, a grace period will be allowed whereby competitors may use the 4 (four) Hoosier LM compounds utilized in 2004 – M10, M20, M30 and M40. A D60 will also be available for the one-mile tracks. All U.M.P. tracks enforce the same tire rule.
Does anyone know what the predetermined date is for 10's & 30's?