Hey Kevin, its been a while... Kersten mentioned that you two and one other person were going to do a suspension evaluation... Kerstens Kore vs yours vs the other guys... did you ever do it? if so did you post results? (hint hint... where? lol).
I yanked the AFE kit when I had just the Magnaflow setup (no kitty), and only when I was on a road trip (to improve fuel economy). So for a while there it was in and out. Back in Sept/Oct time frame I added the Aero 4040 where the kitty used to be and I cant tell you how much it helped out overall... it added enough backpressure (IMO) to balance out the performance so that I get good mileage and strong performance. So my current setup.... AFE (like yours IIRC), ATS intake, Aero 4040 and 30" magnaflow has made me a very happy camper. the downside is the EGT's take a little longer to come down before shutting it down and they may be a little higher than without the Aero. Totally acceptable to me since I dont drag my truck and I rarely tow with it. I think if I did start towing, I'd put a bypass around the aero with a valve (exhaust dump thru a 3rd muffler (maybe) ) A few weeks ago I moved my oldest daughter up to WA and towed a small trailer, truck did awesome and I have no complaints. On the way back we did the speed limits all the way and managed 18.2 mpg over 350 miles before stopping for lunch & to refuel (didnt want to stop again). the previous best on that drive (from Silverdale to Roseburg) was in the low 17's... which was before the aero install and with the stock air box.
I think before I spend any more $ on performance parts, I HAVE to get the tranny fixed... 2nd gear shift solenoid sticks and if I'm on it hard with the TST turned up, 3rd wont hold either. looking to do an HP rebuild with suncoast rebuild kit & a good torque converter... not sure when but it's next up.
2005 QC 4x4 610 CTD
Mods: AFE stage 2, 30" magnaflow, aero turbine 4040, ATS Arc-Flow intake manifold, TST powermax