I would think you should be doing better than that. This heat isn't helping, but that 60' is bad. best I have mustered is 2.2.
Those 20's aren't helping. LT's should be a huge improvement, but I don't think there is any way our big-ass trucks could hit 12's N/A (without dropping absurd amounts of jack).

EDIT: Unless this isn't your DD, then you might need to start with a new cam & 4,000 stall!!!!