thanks so much for info.if i get a 3-71 in it somehow will it pass as a super 99gm so i can pull antique class?or is there someother obvious difference? thanks again   donald young 519 bancroft hwy litchfield n.h. 03052   603 345 3833 my cell#should find me better than house phone.     most any truck work one time or another  right now kind of one man show  also move houses  have 1960 autocar all set up to pull them     you would like to see our hydralic unit in operation  12 15ton jacks all go up unified   for now don   just got called by state to go salt highway   sleet and freezing rain out now   would look foward to talking to you whenever