Possible, but depends on base trip mix and your seniority.

In NYC, there are couple of 5 day trips paying 33'ish hours....two would be 66. Then pick up a normal two day trip worth 10:30 and you are at 76 hours.

Or if you live local and can load up on the one day trips that pay 6/per day, you get 12 of those for 72 hours.