OP, the cam you want to use has an IVC point if 38*. That would probably be ok as long as you replaced the timing chain at the same time, otherwise, I feel that's a bit too late for a 4.8. I've ran a cam with an IVC of 36 (but) on a 4.8 with the stock timing chain. The timing chain didn't seem to be very stretched, so the actual IVC probably ended up in the 38* range. This made my little 4.8 with just a cam and long tubes pull hard till a little beyond 7000. What I ran was a 216/220 on 110+2. The torque curve it had seems to fit your criteria quite well. Torque started picking up fast around 2700, and was pulling hard by 3000. This is not a shelf grind. I used XE RPM High lift lobes. I ran it with the stock converter, but your converter would be perfect.