Which V8 is in that FPV GS advert?

Make

FPV

Model

GS

A seller calls a GS a “Boss V8” and leaves it at that. The badge appeared on both the 5.4-litre and the later supercharged 5.0. What would you ask for before a long drive to inspect? A clear engine-bay shot, the build date and the engine capacity on the paperwork would be my first three.