did ya hit some RR tracks while hogin down on it?.. usually hitting a hard bump while accelerating hard can cause that... rear tires probably lost contact with the road for a split second while you was on the gas.. and the abrupt stop of the freespinning tires snapped it.... used to happen alot in the Dirt Track days.... good to see ya have a block linned up allready.... how many miles were on that block Jeremy?...