Machining a 318 Flywheel for a 360 ?

Doesn't look like my 360 flywheel at all,I have one for passenger cars and one for truck and both of them have the drilling on the back side so I'd venture to say that is a 318 flywheel,if there is a part # on it someone here might know the fact's
Anyone know if this is a 360 flywheel? The seller says its a 10 1/2" for a 360(external ballance). So far I've only seen like the diagrame above with the 3 big holes. Is this another type, and would this type work? Thanks