Motor Fly's are real light if you get the magnesium wheels . had a set on my 68 Cuda . Would polish them on Friday to go to the track and by Sunday they turned back black . The guy I got them from gave the me the lug nuts for them but he did said hold out your hand , he put a steel mag lug nut in one hand and 5 for the Fly wheels and the steel one was heavier than the 5 for the Fly wheels . They were titanium and were real light . The wheels came off of Roy Hills race car . The Fly wheel could be held up with one finger in the center hole and be spun around with little effort . This was many years ago and I paid $150.00 for 2 wheels and the lug nuts . Just fyi . Great project John