Rear shock spring rubs on swing arm...

My new Race Tech shock spring is rubbing on my swingarm on the lower right side down sorta by the rear brake master cylinder. In just a brief ride it significantly wore into a weld bead. The Race Tech/ Eibach (?) spring is larger in diameter and requires an adapter collar to use. I suspect the spring is made in U.S. dimensions and thus is sized differently than the stock metric one. Could be wrong on that.
Anyway, I don't want to grind any more meat off the swing arm, and I'm afraid to grind a bit on the bottom coil of the spring as the spring may rotate on it's perch(?) And I don't particularly want to hunt down a smaller dia. spring and spend another $100. or so... Anybody else run into this issue. I searched and didn't find anything on it. Approx. 5.7 rate spring.