In the high 705,000 numbers there was a running change in the straw chopper drive system. We at first thought I had parts from the earlier serial numbers on my 706,239 serial numbered 9860. It turned out to be that the factory installed a smaller idlr pulley for a 9760 (yes, I thought the 96's, 97's and 98's were pretty much identical except for the motors)onto my combine, which shot craps at 65 hours. The first replacement turned out to be a screw up on our part, and after visually comparing our drive to another 9860, we got everything right. Our rear straw chopper belt was misnumbered as the feed accelerator belt. appently a few of those slipped out the factory door also. Not terrible impressed with quality control at Moline plant on this machine. Combine is a horse in corn, about 30-35 % bigger than our old 9600's.