A Request For A Calculation About My Last Tournament Hand

[David Sklansky]

Not wanting to come back the next day shortstacked, I made a rambunctious play shortly before the day was to end. Nine handed. 300-600 blinds. 75 ante. Two fold. Six players behind me. I push in my 8000 with J9 of clubs.

Making the simplifying assumptions that all other positions have the same calling (or overcalling) requirements, how tight would those requirements have to be such that my play was plus EV?