I was just thinking of the rubber biscut deal too- its some steel plates with rubber inbetween to allow for a little flex and vibration dampening- probably a lot better than a chain drive in this application.
As far as matching goes they do not need to match, you could do a ford 1.6L with a BBC 632 if you wanted to (don't know why you would though).
Chain drives have been done but they seem to be more for two engines mounted in parallell not in series. I'd like to see 2 northstar V8s together- 64 valves of fury.
