Hi just a bit of info for you and hope it is helpful,I've got a 63inch tid,running gear is car radiator fan motor with plenty of power and cheap to buy, low 2-3 amp usage on a 4inch 4 blade prop,two 12volt 40amp wheel chair batteries for power and ballast,two 12volt 7amp batteries for smoke unit,2-3lb of water for smoke unit,8lb of lead in the stern,all up wait is 100lb.goes very well and stops easy,turns well and looks impressive on the water.of you want my rudder dimensions I'll let you know when I can measure it after the boat show this weekend because it's on our club stand.any more help you may need please ask and I'll try and help.