I agree with both previous comments. Would add that i would make the wings level so there is less down force on them when trailering backwords. When i modified a boat trailer i put the light leaf springs (1200 or 1500) pound. I would say thats still not light enough of a suspension. I get a shake around 40-45mph. I think its from not enough weight. Granted, my trailer is quite heavy duty, formerly a 24' aluminum boat trailer. Single axle is all you need. Just be sure of your wings supports for and aft. See the sticky trailering a kf7.