it's the 8 speed. 3.21 rear gear. The 8 speed has a 4.71 first gear, so even with the 3.21 rear end it still has a lower first gear final drive than my 08 with 3.0 first gear and a 3.92 rear end, and about equal for second gear. It takes off pretty quick.
I cruise 80mph at ~1700rpm, in my old truck it was ~2100 rpm.