then a toyota diesel shouldn't be on your list.
there is no support for them here. you will not walk into your local dealership and find parts for it. the local parts stores would be even more confused by it, as it's not even in their systems.
This may be a good point.
Below are the official Toyota specs of both the 12H-T and the 2F. On paper the difference between the two is small.
12H-T
Power output: 100 kW (134 hp)
Torque output: 315 N·m (232 ft·lb) at 1,800 rpm.
2F
Power output 101 kW (135 hp)
Torque output 271 N·m (200 ft·lb) at 1800 rpm.
Yes, but can the 2f run on alternate fuel sources?
For the purposes the OP originally stated (post apocalyptic bug out vehicle), I'd have to suggest an American rig over a Toyota for several reasons.
1) They're larger (depending on the rig). More room for gear and family.
2) Parts: They're everywhere! You can find parts at any NAPA or corner parts store (assuming there's any left standing).
Otherwise, you can salvage or steal them just about anywhere. Remember, we're talking post apocalypse lawlessness.
3) Easier to work on if you build an older rig minus all the e-gear.
4) Other than a Dodge, they might not rust out from under you as quickly as the Yota.
Now you could always swap over mostly GM/cummins running gear from the engine to the diffs, and have a cool looking, unique rig with the power, longevity and durability you'll need in that new world you're talking about.
As for fuel sources, they both have advantages. Diesel is safer, and you have the ability to run alternative fuel sources.
Gasoline is cheaper, and may be more readily available and plentiful (remember, you're probably going to "borrow" it from the less fortunate) than it's diesel or bio-fuel counterpart.
I love my FJ62, and would love a diesel.
But for what you're talking about, I'd at least listen to those recommending either the SBC or 1HZ if you're hell bent on a diesel conversion.