First, use 4 of the same diameter wheels. The front pillow blocks are slightly curved, rear pair is straight. Front units go with pillow block down (axle under runners) at around the point where the sleigh joiner doubler is. Put it on the inside of the runner.

Rear pair goes on the inside of the runners about 1-1.5" behind the CG. Turn it so the axle is up over the runner. This gives a slightly positive attitude so the model will rise off smoothly with speed and not leap or jump off the runway. There is no steering, just set it down into the wind and go. It won't be on the ground long anyway. ;-)
SKU Number: RRCSSWSAGM