What did the "C" stand for originally? "Centrale", perhaps, as in mid-engined?
Lamborghini used the "TP400" designator for the Miura to distinguish it from the LP500 Countach. It stood for "Transversale Posteriore", 400 centilitres (transverse, rear engined, 4-litre).
I don't see why you can't keep the 6C moniker, even if the car doesn't use the same drive train as the original. Its certainly got more Alfa content!
I called my Nova a T33 because I wanted to draw attention to the "tubolare" chassis, but I'm using an Alfasud engine, not a 33 boxer, so really it should be called a "T-Sud"
Lauren