Flux radio box has 30mm clearance from the mount point to the bit of plastic that would hit the base of the servo.
Looking at the diagram here
http://www.savoxusa.com/ProductDetai...Show=TechSpecs it doesn't have the dimension from the base to the mount point like some of their other servos. Doing a rough proportional calc though off the diagram I get about 31mm. So likely you would have to modify the radio box.
Btw, that servo is brushed not coreless.