[1985 CCX]

Not sure it references anything more than the standard comp or S/C? Sounds like the comparison is to the redesigned 427 Cobra versus narrower 289 on the previous page.
3020 is extended however that was probably done for Tom Paynr after the first set of rear fenders. Early pics show it tighter.

Remember referencing cars in pictures is not accurate way to go about replicating it.
Wheels could be offset and the car could be rebodied.