ive got an 01 se 4x4 and i want to put 31's on it. ive read about people just haveing to tighten the torsion bar and get an inch of lift out of it. does the truck ride ok after this and how much does it cost to have a shop do that. do you have to get both front and back re aligned after that. are there torsion bars in the back. i dont even know what a torsion bar is so bare with me. lol. also whats the differance of a 31 tire and a 16/70/somthing. whats the widest tire you can put on the stock rim.

No need to adjust the torsion bars for 31" tires. Doesn't change the ride much if at all, and a shop would likely charge an hour labor for it. But since it requires an alignment, you could probably just request an alignement and tell the tech to raise the ride height while he's at it. There's no "rear alignment" to be done by the way.

The bars are in the front, from the back of the lower control arms to a crossmember under the front seats. Hard to miss.

so will the front be as high as the rear when you tighten up the torsion bars. also is a 31 the with of a 70 tire?

Yes, raising the front end will pretty much equalize the front to the rear.
The 70 part of the tire size spec describes the sidewall height as a percentage of the tire width.
31x10.50 is pretty much equivalent to a 265/75-15 or 265/70-16.