On Jun 27, 12:30*pm, cavelamb himself wrote:

Can you do the weight and balance calculations?
And performance predictions?

That's what I thought...

I'd need help with the balance (CoG) since the nose would be about
70lb lighter (based on engine weight alone, not sure about mounts).

Would have thought performance would be similar with Jabiru @170hp and
the Lycoming @ 180hp.

I think the fuel usage would be better with the Jabiru.

I'm considering building a Falco, but as an AUS based builder I
thought a local engine (of a more modern design) might be an option.

The Falco is a great aircraft, but I see no reason why all aspects of
the specification need be stuck in the 1950s. I'm all for glass
cockpits, updated systems and a more modern powerplant. I have no
plans to alter the look or aerodynamics of the aircraft.