Hi John,
A solid shaft and surface piercing drive in the Intercepter hull is no problem at all; I've just finished two 65 cm hulls with it and they run well.
The trick is to have a shaft that's as long as the correct position of the CoG allows for, the motor as far forward as possible, so the shaft exits the transom at a very shallow angle:
The propnut should be between 10 and 13% of the hull length from the transom, in your case between 60 and 78 mm.
The motor should be as close to the bottom, only the watercooling coil should still fit.
I use a bulkhead for the motor to spread the load, a good thing in an ABS hull:
Topview:
The motormount/coupling bell is a great benefit, no need to allign the motor and propshaft, this sorts itself out when the motor is bolted on, here in a 65 cm stepped hull:
Mind you, these boats run on electrics, but nitro shouldn't be a problem either, the principles remain the same...
Here's a clip showing the boat in action:
http://www.youtube.com/watch?v=HLcMharve1kSo, yes, it works!
Regards, Jan.