I still have a Hemi Truck also.
Heads, Cam, long tube headers, no cats, true dual 3" system, torque converter, HyperPac programmer, K&N, wires/plugs....probably in low/mid 14's realistically, maybe high 13's, but haven't taken it to the track (daily driver). QC 4x4.
I would have to lose 1000 lbs to get into the 12's right now. A RC is about 500 lbs less. Some weight reduction and you/he could get there.
I have a split second controller for the cam, and it is not a huge cam. So I don't know how he is getting by without some sort of programmer for the cam? Possible I guess, but like the rest, there is probably more than just a cam. Large cam will throw the idle all over the place and would have stalling issues with the Hemi.
Post this on one of the Hemi Truck forums and see the responses.