You'll need a different clutch disc, since the input shaft has 25(?) splines. Call Rick at Sunbeam Specialties, he has a disc with the right (big) diameter and correct splines. Too bad you still have to use the series II pressure plate. Man, they're expensive...
You'll also need the newer shifter assy., and front yoke for the driveshaft (also has many more splines).
Otherwise, an easy swap (if you consider taking the trans out of one of these easy).
gary strom series II