Lets see 696 RWHP = ~ 900 Flywheel BHP. We know torque = hp at 5252 rpm, so lets say the power shift at 5000 was 85% of total engine output, thats roughly 780 ft lbs through the 833..
23 splines are very tough, and work behind some very strong big inch wedges. BTW, looks like the 23 spline...