Fwiw MOTEC LS conversions are legal in CA :-)

As a note to the OP, Our long tube headers do make a very noticeable increase in down low torque. They have gone through 7 design tests before settling on our current offering. You can expect to have your Tq and Hp power band come in 600 RPM sooner and total increases over stock of 30 Wtq and 25 Whp. It may be important to note that our header systems are not smog legal for on road use in CA.

RIPP

I did the LS 5.3 little over a year now. no complaints, lots of power everywhere i go.

Ripp Supercharger Blows
 

I had the same question, should I install a supercharger and if so, which one. I did some research and came away with the Ripp Supercharger being the way to go. This was because of the inner cooler and because of problems I'd read about with other superchargers. Unfortunately, I did not find out what I needed to before I bought the Ripp. Fortunately, I bought it through 4WheelParts and had them do the install. They were awesome. Ripp was not. The supercharger was not. I'll net it out to just a few things. First, shifting with the supercharger was unpredictable. The idea of having to let off the gas to shift isn't very palatable when you're trying to pass another vehicle. It was very common for the supercharger to cause a transmission stutter of wanting to shift but not quite shifting. I felt it was unsafe. Second, cruise control does not work with the Ripp Supercharger. Apparently, both of these problems are known issues, but Ripp doesn't tell you that until after you've installed it and you're calling tech support. Last, after 1700 miles, the supercharger started whining extremely loudly. 4WheelParts said it needed to be replaced. Ripp wanted to rebuild it or replace it with a used rebuilt one. After 1700 miles? 4WheelParts thought they were crazy too. Needless to say, I removed the supercharger and went back to stock. 4WheelParts gave me a complete refund. I have a feeling they won't be doing a lot of business with Ripp in the near future. I sure won't.

I wouldn't trust the monkeys at 4wp to change my oil much-less install something that requires programming and could potentially wreck my motor.

I had a RIPP SC on my '08. Loved it! Ross and team know their stuff. I highly recommend their SC.
I now have a '15 with some mods and I can say off the line the '15 is better than the '08 but at higher speeds the '08 with the SC wins.
I will say I did take a hit with mpg when I added the SC on the '08. Then again I was running 35s and about 600 lbs of extra hardware.

I have had my RIPP SC for about 2 1/2-3 years now (25K miles) and I LOVE IT!!! I started with the Headers and it just was not enough. My 2door is HEAVY (5300 lbs dry) and I use it as a daily driver everyday and it is a pleasure to drive.

As for the LS/HEMI crowd I would agree that they may be a great thing but I think you are comparing apples to oranges. The RIPP cost about $5K and can be installed in your garage in about 1 1/2 days. Best numbers on an LS/HEMI with the kits, engine and mods that have to be done is 15-25K? and a lot more time!!! I know there is going to be somebody out there that says they did it for 5K but that story normally ends up being they got the engine N/C or some other story like that.

Spend 250 bucks on a Southwest ticket and fly to Phoenix and I will take you wheeling and let you drive it!

Have the ripp on my 2012 3.6 with about 15k miles on it. No issues and very worth it for me... wouldn't be able to go back. Its also easily installed with hand tools.

I have a RIPP SC on my 08 JKU and love it. I've had no problems at all and I'm running 35's and 4;88s. No hit to mileage and very minimal surging. 103k on rig and have no plans to change anything right now. When this engine quits, the LS swap will be the way I go.

Not to side track this thread but we have been incredibly happy with the Sprintex Supercharger. The intercooled kit is very easy to install and makes good power. PM us if you would like to learn more.