yes to # 1 and yes to #2 but with minor changes. the 200 started being built with 7 mains IICRC in 65. the only other difference would be the oil pan, oil pan pick up, and the carb bore. the 66 is a 1.5" carb bore vs 1.75" for the later model. just use the pan and pick up from the 66.and the carb from the 78/79.