I have been offered a 9.9 1968 Chrysler O/B. I wondered if parts would be a significant problem if I happen to encounter problems. The gentelman who has it for sale says it was running well last season and has now been in the garage for 8 mos. He is proposing a price of $100.00. I have a 12 ft. Harbercraft tinny rated for 10H/P. The transom is 16 inches deep and the shaft on the O/B is 17 from the bracket to the plate above the prop. From what I can gather from some very knowledgeable people on this forum the shaft lenghth ought to be about right on. Thanks to all for such excellent advice so far.