Betcha didn't know a 1998 100 is very similar to a 2000 Tundra.
**Not even close! Axle shafts, control arms, 100 has torsion bars vs coilovers, etc. They share and engine and a few parts though contruction wise they differ a lot.
Take a look at the thread in General Vehicle about improving payload capacity. Mike H has a great post toward the end about what you need vs what fits and what's reasonable. My truck is basically a 100 with a bed and fewer creature comforts
**Some addressed above. Not even closely correct. Have you ever even looked under a 100-series? The Tundra is a completely different beast built and designed for a different application.
Your difficulties with 315s will arise primarily in the front end, and they will be bad.
**Where and how did you determine this? What are the facts? My facts are that at this point there are loads of 100s running 315's. I've run 315's for about 80K and with no issue and/or breakage. What is "bad" on a 100-series (not some other truck) when running 35's?
Like SchottsCruisers says, you need to figure out your intended use, because (ab)using a 35x12.5 tire *will* eventually result in carnage in your driveline if you don't make some substantial upgrades at least in the front end, and if you are not (ab)using a 35x12.5 tire, there's no reason to get one.
**Totally unsubstantiated and just wrong. Respectfully. Again, we're talking about the UZJ100, not just about "running 35's on some regular-ole truck.
Carnage is a function of required torque at the hub, and the amount of weight that must be lifted to climb a hill. Putting a 6K# truck on 35s with a stock drivetrain is fine if you're never climbing anything, but if you start really getting it, you'll find your shoes are too big and simple physics will break your axles (also possibly deflect your ring and pinion away from each other, run shallow and break), particularly with a locker since you'll put yourself in positions where one axle on each end is trying to lift the entire truck.
**Again, complete plain ole bad information regarding the UZJ100.
You really don't want to know how much a "proper" axle costs for large tires, three tons and a V8, but in general a complete build at both ends costs twice your figure above and that's before wheels, tires, steering and fitment--and your payload capacity takes a hit since those parts aren't light, either. Three tons, large tires and large engine on difficult terrain pushes you in to the Dana 60 range of parts, which get downright stupid expensive.
**No axle upgrades are needed on the UZJ to run 35-inch tires. In fact Alan Podvin has been running 37's in Moab, AZ and accross the West and with no carnage. 80 and 100 series axles are rated comparable to Dana 60 axles. (FYI)
There's no need to go that route with a medium wheelbase, good approach, departure and breakover angles, a sturdy drivetrain, and 32" tires that will adequately get you almost everywhere short of difficult trails. Are you building a rock crawler or an expedition & adventure vehicle?
**Good questions
Add to all that the need for a lift, which actually decreases your capability and weakens your forward drivetrain.
**Not on a 100-series Land Cruiser. I am puzzled by this comment?
Your wheel wells are also similar to mine, you can fit 35s with no lift with a bit of work. Get proficient with a BFH, sawzall, air chisel, die grinder, body saw, and 0.023 wire in a MIG welder, because all those things are necessary to properly clear a 35x12.5 tire on a Toyota.
**Huh......are talking about what we are? The 100 series?
If you get a chance, take a 100 for a test drive in the dirt. Trust me, there's little need for 35x12.5 tires unless you're really getting in to gnarly stuff, in which case you're better off getting to know the capabilities of your rig in stock form and slowly building to the vehicular needs of a 35" tire...add that tire now, with stock parts, and you'll find you're staying off the harder stuff where a 35" tire is a necessity because you'll break your front end.
**I think I understand now. This was all a joke and I got sucked in. OK, laughs on me. If it's not a joke...respectfully, you need to not post these completely inaccurate statements. You do nobody any good.
Get one...it sounds like you have a plan and a desire to make it happen. Enjoy it in stock form for a while! You'll be amazed at what a stock Toyota, Jeep, Nissan, etc. can do in bone stock form. Build it slow, learn the shortcomings and fix them as you have time, money and a real need to make the changes. Otherwise, you're throwing money away on equipment you're not familiar how to use with the vehicle you've just purchased.
-Sean