Is there any special fitting process?
As long as its in good condition : has good oil pressure, does not use any oil, and no crank case breathing, then the process is quite straightforward to many standard or pre-modified.
How is Ignition Controlled?
Ignition control can be from the standard distributor or a mappable one.
Can the kits be swapped to different engines?
Kits can adapted as your engine is modified further or swapped to a larger or smaller engine with minor changes.