IMO, believe 74” is oversized (And by my interpretation, by more than a little), and will likely get levied as ‘oversize’ So I’d prepare for that.
Its certainly possible that that an agent may let it go, but at that much past the cutoff, I’d doubt it. If it’s an inch over, it could pretty easily be seen as within dimensions, but at 10+ inches over, even a newbie agent can probably tell. I’d expect to pay, particilarly if at a station that is staffed by contractors.