Anything is possible with tools. I don't think there is a direct bolt up but I would think that with a cutting tool, welder and measuring tape it would be possible to make a mount for the new final drive, cut the swing arm to a certain lenght, weld on the new bracket aligned correctly and adapting the drive shaft. Possibly needing the drive shaft from what ever bikes final drive you need.
Or you could do the cx650 clutch mod. And if you need more put on the wheel of a 78 cx.
Or you could do the cx650 clutch mod. And if you need more put on the wheel of a 78 cx.