Radiator to K Member support

Probably would depend on how fast your scamp will be going. I was trying to think if I ever had a car that it was removed on and couldnt think of one so I don't have proof but you would likely be fine. The tanks on a radiator are pretty stout across the span at least on the thicker cores.
If it ever did give a problem i would think you would see it in a radiator leak at a tank seam from flexing. This is just a guess of course. I really think you will be fine without it. The radiator is only attached at the sides.