Loki,you`ve answered your own question...a few observations,;the 73 probably started from the end of the runway,or an intermediate close to it,and he would/should be able to stop in the event of a failure from about 80-100kts,so I suspect you started from another intermediate,if as you say ,you couldn`t stop.Runway behind you is wasted if you had an engine failure ,or a tyre burst.
In a light x-wind,wake turbulence will take longer to dissipate across the runway,so you should give yourself about 4 mins,from the end of the runway.You should be airborne and above the turbulence before the area that the heavy rotated at. If you go from an intermediate position the vortices are probably still descending/dissipating..
Suggest you google `Wake turbulence and separation distances for take-off and landing aircraft`...Lots of info around...Safe flying,but make those considerations before you open the throttle...better to be a bit late `down here`,than early `up there`....