Good point embee. But I'm not sure that the SP1 rads were ever supposed to be solidly tight to the frame. As with the third mounting point on the SP2's. Someone here already pointed out the SP2 was a lot of correcting issues with the SP1. Such as leaking weld on the gas tank, judder spring and seat for the clutch, and the rads.
I checked the condition of the rubber mounts, which are sleeved with a spacer, specifically to prevent rigidity. Apparently. Because when I tighten the two mounting bolts, the radiator still has a small amout of flex, provided by the rubber, sleeved bushings that are part of the mounting bracketry.
So, I thought there was supposed to be some movement, and that it would be better than a rigid mount.