Welcome to the board, and thank you for your service to our country.
Unless you come across a used 4" IFS suspension lift in good condition and dirt cheap I wouldn't bother w/one, there are two cheaper ways of getting the lift you need to clear 33's.
The cheapest would be a body lift, next would be a 1.5" ball joint spacer lift and 3" longer rear shackles. A combo of the two will aloow you to run 34's or even 35's.
This is my '90 w/a 4" Trailmaster suspension lift and 33x12.50 on 15x10's w/3.75 bs:
and my '91 w/o an IFS suspension lift on 35x12.50 on 15x10's w/2.5" bs:
To get the lift I used a 2" body lift for the cab, 1.5" ball joint spacers, beating the firewall back to the first body mount, and I used an additional mainl leaf spring in the rear and 3" longer shackles to match the 1.5" BJ spacers. I cut 2 inches out of the fender not to clear the 35's w/IFS, but fior when I do the straight axle swap sometime in the future(built the truck 3yrs ago). Here is more info on
Ball Joint Spacer's here, as well as price, installation info and photo's.
4Crawler also has other products he sells and a lot of quick fixes/diagnostic/helpful hints on his site as well.
32x11.50's on 15x8's w/3.75 BS will fit the stock suspension and only rub on the inner pinch seam along the firewall, so you should be able to clear 33's w/a just the ball joint spacers and beating back the seam.
A 2" BL will also allow you to clear 33's but you might need to beat back the body seam. That is what I had to do to clear 33x12.50's on 15x8's w/3.75 bs on this '86 I restored/built a few years ago.
For a rear locker, I would go with an ARB or a Toyota electric locker(will have to modify housing, or swap in a Tacoma axle). The option of being able to only use the locker when you need it is worth the extra price, and you can get complete diffs w/gears and ARB installed for from Marlin, or others. I only paid $1150 for the one in my '91 from
Davez Offroad Performance. Check around your area, you might find a local shop who sells them set-up that way so you can save on shipping costs.
If you are not sure what tire size you are going to run, I would opt for the 5.29 gears. They are a little tall for 33's, but a lot of people w/22r(e) engines find them a nice fit over the 4.88's which are the correct gear for 33's. These
Auto Calculators and
Marlin's Transmission Gear chart will give you an idea of what your engine speed will be with the different tire sizes and gears.
Davez Offroad Performance sells(used to anyways) tube doors, last time I looked they were about $200 a pair.
Don't worry about wheeling IFS, you can do more than just mild terrain, especially once you add a rear locker and dual cases. You just have to be more careful of what you are doing, make sure you are picking the right line, and be mindful of the skinny pedal. I wheeled my '91 on the Round-up in '07 and didn't have any issues, even passed a few SA's rigs who were having issues w/the trail, though more from a lack of their wheeling experience than their rig.
