Since I've not decided on a CAI yet, I simply cleaned the stock air box, and replaced the filter with this "high flow" stock-fitting version:
https://www.amazon.com/gp/product/B06XYKVL2G/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1. I noticed an immediate increase in acceleration. The old filter (Mopar) wasn't terrible looking, but overdue for replacement.
WARNING: Long read. Might be worth it for those who haven't changed plugs on a Hemi before...
The next day I attempted the dreaded Hemi spark-plug change using Champion RE14MCC4 570. It was my first time doing this on a Hemi and so I did my research, watched the videos, bought the wobble extensions. Though I didn't bleed, I managed to bellow a few unique colorful metaphors before all was said and almost done. Previous owner either avoided anti-seize goo, or over-torqued a few plugs, or both. I did this on my WK that had sat overnight so the engine was cold. The passenger side wasn't terribly over-challenging, accept for locating the dropped coil-pack bolt. Spied it fairly quickly though and reached for it with my magnet and just as I had started lifting it out, it touched a hose on the way up and fell quietly to the engine's depths under the alternator, somewhere good and hidden. Note to self and whomever reads this... buy a MUCH stronger and extendable magnet. I should have taken it as an omen because, other than the radiator's overflow tank bolt, it was the very first bolt I removed. But things would get worse.
Rather than looking for the elusive bolt, I decided to start working on the driver's side, front to back. Seemed like this engine was specifically designed to come with obstructions to the spark plugs. The next group of hours of effort would be mostly fruitful but with yet more frustrating delays. Note to self or others... before ever doing this insanity again, buy a brand new highly reputable brand of 5/8" spark plug socket, with a rubber plug-tip grommet that WON'T COME OUT OF THE SOCKET. I had an old Stanley socket that would later find its way to my recycling bin. The grommet would come out of the socket, and stay on the plug after insertion. I would eventually remember where I put my Gorilla glue but not until I went thru the extraction and insertion process way more often than I should have. After 4 more plugs were done, I decided to look again for the missing bolt. Crawled under Jeep for the 3rd time, and just started contorting my hand and fingers, reaching into every crevice, cranny, goo and grime, and got really lucky! Scored a major victory with that find!
Feeling re-energized, I started tackling the last 6 plugs closest to the firewall. I really wish I could have moved the fuse-box, and the power steering reservoir as doing so would have allowed much straighter leverage on those plug chambers. While removing the 2nd last coil pack, my now rather fatigued hands managed to drop the old-school Craftsman ratchet... prayed I would hear it hit the garage's concrete floor... but of course not. Why would anything be easy? I'm nearly 8 hours into this project that should have taken less than 2. At least I could see the bugger. I went to the basement looking for some very strong magnets that came out of an old hard disk drive - I figured I'd tape one to a stick, but like I said, why would they be easy to find? Why would they be where I last left them? Because I have two curious young boys of course. So much for my MacGyver trick. I knew my other magnet would not be strong enough to lift it out, however, it proved to be just strong enough to rotate it closer to the radiator area. I crawled under from the front of the Jeep, and found a place to reach part of the ratchet with my fingers and maneuver it out. Whew! Another victory as it was my only 3/8" drive ratchet.
Finally to plug #16, closest to the driver/firewall. Stuck as a constipated dino in a tar-pit. I tried numerous combinations of wobbles, u-joints, and regular extensions, trying to get straighter leverage, used a pipe on the ratchet for more leverage, but could only rotate the plug a single click at a time, and the threads on these Champs are ridiculously long. Several times I could hear what sounded like the ratchet gear failing - CLICK CLICK CLICK - while under too much force. It might have been the wobble connections sliding instead of gripping though. I had two big burly neighbors try to rotate it as well and same thing. They thought if they tried any harder, something awful would happen. I relieved them and wouldn't ya know, 9 1/2 hours into this and DAMN, down goes the freaking ratchet AGAIN... but the curses changed to hallelujahs when we heard it hit the floor. Tried one more time after I sprayed some PB Blaster in the chamber and of course, now the spark plug socket keeps getting stuck on the plug. Found my dad's old fish hook extractor (looks like narrow alligator teeth) and managed to squeeze hard enough to extract the socket.
Enough was enough. I left the old plug in and buttoned everything up. Test drive did not throw any engine codes. More hallelujahs. Not one drop of blood, but not one part of my body didn't ache and beg for a strong whiskey sour! The neighbors had their firepit lit up, so that's where I finished my night... until the looming downpour put the flames out.
Gas mileage calculations from Jeep computer: I used to average around 17 mpg highway, straight and level. After the 2" lift, that didn't change much. I went from 245/65/17's to 265/70/17's and gas mileage dropped over 2 miles per gallon. After the air filter and spark plug change, I'm now getting 19 mpg, highway straight and level. THAT surprised me - pleasantly so of course.