Most of the Magna internals will fit in the halo shells.
The raceway and drive system is fully compatible.
The issue will be with the wiring harness and with the circuit board connector as noted.
With the wiring harness the motor wires would need to be shortened and the battery wires lengthened. The connector on the back of the board is a bigger issue and may take some finessing to make it work. I know quite a few people have done this.