[ALMACK]

The way I read the rule book under Stock, only the V-8 vehicles must have an SFI bellhousing.

Or....all vehicles running 11.49 or quicker.
So the Focus could technically run under the F/S index of 11.80, but not by much. Or add weight and run G/S

Either way the Focus would need an SFI flywheel and clutch assembly as well as a SFI harmonic balancer ( unless it uses a "hub" )


Since the car has a transverse arrangement, this is the closest I could come to in the rule book:

All front-wheel-drive or transverse-mounted applications using a
clutch and running 11.49 or quicker, for which an SFI Spec 6.1,
6.2, or 6.3 flywheel shield is not commercially available, must
be equipped with a flywheel shield made of 1/4-inch minimum
thickness
steel plate. Shield must surround the bellhousing
completely
except for area of bellhousing adjacent to differential
and axle shaft. Shield may be multi-piece, with pieces bolted
together using minimum 3/8-inch-diameter Grade 5 or M10
class 8.8 bolts; may be attached to engine and/or bellhousing.