If you have to change it, I'd go with a 5.7 liter of some sort and maybe a 4l80E, d300, heavier axles. Oh yeah, don't forget skid plating, lockers, winch, 4 link front and back,hydro assist steering and brakes, and at least 35's.
They may claim that the oil won't break down until 20K miles but you will still have a years worth of floating metal in the oil which wears out other parts. I'll keep changing my oil regularly like always with regular dino juice. BTW, yes, short trips are bad for your car. Ever start your Jeep...
If the existing engine works and you aren't dying for more power, why waste the money ? How about a gear swap to give you a little more performance being that you have 33's? Who would do the swap, I assume a shop ? Any idea how much that costs ? Don't forget that when you double the power with...
^^^ what he said, I'll add you'll see a drop in gas mileage once you level it and add big tires, not to mention the gutless feel. Light bars look cool dude but I wouldn't own one unless I needed it. Put the money in an IRA.
Because when you buy big tires they are bigger. Also, the wheel elves grant you 3 wishes, you didn't know that ? Oh wait, it must be because when installing larger, WIDER tires, you need the backspacing of the wheel to space the tire away from the Jeep or they will rub when turning, or something...