Re: Running rough in 4th at low RPM
First, welcome to the forum.
I'd recommend you first check the resistance of the spark plug wires. If they haven't been changed in 80K, there is a pretty good chance one or more are going bad. The old "rule of thumb" is, no more than ~10,000 ohms per foot of wire, but they should be quite a bit less. To give you an idea, I still have the original wires off my 05 Hemi LX (~20K on them) and one wire, about 3 ft. long reads ~12,000 ohms for the whole wire. I changed over to the Taylor Shorties, and they've been fine, plus it gets rid of the "rats nest" over the top of the engine.
Also, what kind of plugs did you put in it? Some of the early Hemi's don't like anything but copper core plugs. Others don't seem to have a problem.
05 LX/RT & 06 WK/GCO, modded similarly, MDS "ON" Light, Vortex Gens, Debadged, DashHawk, BT Catch Can, SRT CAI W/Add Air Inlet, K&N Filter, Sonnax Trans Press Booster, SC Tuner W/Adv Trans Tuning App, DS Tuner, Cust tube headers w/3 in. catback, Bilsteins, SRT frt/rear bumpers, Eibach SRT Lwr Sprgs & Sways, FRI Sidewinder Cam Adv 2*, 6.1 valvetrain, SLP 25% UD Pulley, BBK 90mm TB, SOS Coils/.060 plug gaps. 20 in. SRT Reps.