You've got several options. As it's a 4x4, you have torsion bars for front suspension. As it's a 92, it's probably got a few miles on them and they're aren't as strong as they once were.
So you can get an inch or two out of adjusting the torsion bars upward. There is actually a factory spec for how much to adjust them. You can find it here
http://www.blazerowner.com/zheight.htm To adjust them, jack the front up and support with jack stands under the chassis. You'll find the torsion bar adjusting bolts about the middle front side to side at the rear end of the large torsion bars. Turn them in to raise the front. Take it off the jack stands and bounce it a couple of times to settle and then see if you've reached the height you want. You'll need to get it realigned afterwards.
For the rear, your choices are add a leaf or shackles.
You could also (or instead) install a 2 or 3 inch body lift.
There are a couple of 4-5 inch suspension lifts available as well. More work but more results.
Serious lift can be achieved by ripping out the front suspension and differential and replacing with a solid front axle. Not recommended for the feint of heart.
How much and which lift will depend on what it is you're trying to achieve.