Alright...
I saved some cash and I am finally going to really start on my 03' tracker

Currently it's a 2.0L all stock with a 5 speed
has a 2" RRO bl and aggressive 235's

I am going to start with the following
1" coil spacers and a custom suspension lift using some skyjacker parts from my local 4by shop probably only an extra 2" (may do some diff height adjustments for the front cv's)

tires - well from what I can tell all I can go max is around 10" at max with 3.75" backspacing (too much bs and the body will rub, too little and the fender)
so i think the 31 x 9.5 TSL radials are a good idea
I will get 4 on daytona rims (rockcrawler i belive)
and have the center siped 1/4 inch

right now though, I am scared the stock drivetrain being a 2.0L may not be strong enough as the r&p as I am now told is 4.60

I was also told NOT to change my transfer case gears as in my location (now calgary alberta)
is usually mud bogging and not rock crawling as they only have some sandstone and I need more high speed power than crawl torque

the option for r&p is 5.12
but this is the thing, the current a/t's I have are probably the best winter at's I have ever used
as compared with some friends' wranger at's, bfg ko, cooper a/t's etc..

I want to keep them for daily and winter drivig

if I change to 5.12 that may be too much rpm for the 235's
and I'm not sure if the 4.6 is enough for the 31's

as I need more speed than craw ratio... the only alternative to changing r&p is some engine modification...
or better yet... a diesel conversion as there is a 2.0 L from japan/australia

what's the chances i can get JDM to bring in a 2.0 diesel?

(I will be running a front LSD and a decided to try a rear locker)

I belive all said and done if I have a 2.0L diesel which has closer to 200lb of torque
enough clearnace using 31's and the suspension lift
and the locker/lsd traction adders
the little rig will be a very awesome little on/offroader

please your opions and thanks in advance

Go buy a samurai or an older trackick and have fun with it and leave your 03 alone.

i wish we had diesels over here in australia.

*sigh*

well, we get ours from japan too.

and a '03 lifted and ready for trail is something sweet, i wouldnt be game to drive it hard. maybe you can pick up an older tracker/sidekick for cheap, and probably spend half the money to get it lifted and locked, and then who would really care about if it gets driven into the ground or not.

great project, and plus, u'll still have the '03 daily driver.

other than this, i have no more advice due to very little knowledge about the newer models. (97+)

good luck and have fun.

I have to ask, but why are you needing a lift? Is it difficult to get around when off-roading on the 235's? Adding a lift, usually brings an aggressive larger tire. A larger tire brings changes to r&p. R&p change usually brings lockers. So it's a revolving door of affect and effect.
Why not just carry a set of wheels/tires for changing to an aggressive tire?

I would keep the 03's 4 cyl engine and drivetrain (cost & durability vs. downtime, hassles, etc). I would suggest that you don't look into an engine swap, you'd be better off with a second vehicle for that. Thus a second vehicle could be used exclusively for harder trails, rather than the moderate ones. If anything, see about doubling up the t-case or go with the low gear set. Since you have a 5-sp and not an auto, the lower gear set wouldn't hamper the performance of off-roading. It'll actually make you a better observer of the terrain and which gear combo in the tranny/case to use.
Think of it as a mountain gear bike scenario. You have 3 pedal gears along with up to 7 other gears to use. There are points where they will over lap and where you are too high (pedaling hard/slow) or low (pedaling easy/fast).

Your current AT's probably come in the larger size you are looking to run, so see about getting credit for your existing tires and step up to the larger size.

If you are wanting to better the off-road performance of your 4-dr, I'd look into going suspension lift, body armor like the kick panels, under belly skid plates, adding proper gears for tires, adding lockers as well, adding larger diameter tires with minimal width change to stock, add a lower t-case gear set or doubling it, and pretty much call it good till I re-evaluate my on/off roading requirements. Since you use this vehicle everyday, you will want to keep it civil for that. I suggested keeping the tires near same width, as you go larger in diameter, tires usually go wider. Problem is that adds weight and rolling resistance. With a set of gears to match on paper to the tire size, there is little to compensate for the extra resistance. Most step up to the next lower r&p to compensate for on-road accelaration and at speed acceleration, especially with a small engine.

I suggested a few things, but I'm not in your area. Driving with a rear locker will change your habits in the ice/snow at speed situations. Good luck.