Sure Grip (hopefully) question

have you verified that it is a sure grip? with only 1 tire leaving tracks I would doubt your rear is the sg style. at this point I believe the only way to tell is drop out the 3rd member & visually check the carrier for a sg unit

a 741 pumpkin could have anything at this point in history. if you are only spinning one tire then I think you have a common single spinner rear.

Lawrence