Early Intairco wheels did not have the tyre clamped, the latest type do.
C-36/2 are the best set od air retracts ever made, my 10 year old Classic Flash proved that again this weekend still holding air and operating perfectly.
Airtech Germany make the new sets- with high speed wheels.
personally I would assemble a set using the Behotec set, nose leg and wheel it was designed for and Intairco 83mm wheels and brakes. I use Jet A1 main legs in our sets, but guess they are hard to find in the states, so maybe Dreamworks have some 6mm pin, 1/4" axle legs
In the UK where there are a lot of Flash and UF models flown they pretty much all use the above.