I have a Unique 289 FIA that I am just finishing.
On the rear:
315x35/17" BFG G-Force Radials on a 3 piece Compomotive 12.5 knock off wheel
It is putting down 12.5" of rubber on the ground
On the front:
275x40/17" BFG G-Force Radials on a 3 piece Compomotive 9.5" knock off wheel
As you can see they fit nicely with no interference.
Terry C