Congratulations on the big wheels, Sheryar! You've taken a very brave plunge, for which you need to be thoroughly commended. And now that the congratulations are over, let me share some of the nasty stuff with you 
I have a feeling that nothing less than 4.5 inches suspension lift (along with maybe an inch body lift) is going to work on those big boys. The 70 Series just isn't designed to accommodate such large wheels, stock. And even then, it's quite possible that some body mods (shaving the wheel wells etc) may be required, even AFTER the lift.
I have no idea about the rims offset, but with such broad tires, there may still be some rubbing against the rods/ends etc, so you might have to look at fitting some spacers, after the lift.
I'm going to post a diagram at the end of this message. If you see the extreme left column, it will show tire sizes. If you see the top row, it gives the differential gear ratio. The rest of the diagram consists of yellow, green and red colours. Yellow means "economical but underpowered". Green is "perfect power and economy". Red means "overpowered, and uneconomical". Now...your tire size is 38. I think that your 70 Series is a 4.11 ratio (but you can get it checked from your mechanic). Now, if you connect 38 and 4.11, you will get 2362. This falls within the Yellow Zone (just barely), which means that your vehicle will be economical but very underpowered with these wheels. You are going to require at LEAST 4.88 diff gear ratio for your vehicle's performance to fall within the green zone. Here, it's worth mentioning that I HAD to get a 5.29 ratio, because the Phantom has 42 inch wheels.
So remember, brother...if you plan on running these wheels, you should keep the following task table in mind:-
a) Correct diff gear ratio.
b) Proper lift (suspension and body).
c) Steering geometry and stabilization.
d) Wheel spacers.
All of this may appear as if I'm trying to frighten you, but that is definitely not the case. Since I have undergone this exercise myself, I am just offering some advice on how you can go about tackling the project. Here, I must say that it's incredibly exciting, and has a huge amount of potential. I wish you all the best of luck with it.
Regards.
Fouad.
