I have a 96 blazer and I’m trying to clear 31/10.5r15 on stock rims, how much could I safely crank my torsion bars?

 

31s are a snug fit. I cranked my torsion bars with stock keys until they maxed out. Unfortunately my torsion bars have sagged so that I didn't get as much lift as I would have liked. I have replacements to install later with after market keys. Stock keys should work but replacement ones would ensure you have enough travel.

I would suggest you take measurements before and after you make any changes to document the height change.

Be aware that with a torsion bar crank, the upper ball joints take a beating. That us why I installed Rough Country upper control arms. (See my build thread.)

Know also that with 31s, a bit of trimming of the front wheel wells will be necessary. Another thing is that because of their size, 31s will rub the frame rail when the steeting is hard over. This is why I went with 30s.

 

No more than 1 1/2" to 2". Otherwise, you will be replacing/rebuilding your front end on a regular basis. If memory serve, one full turn on the bolt will give 1/4" rise or drop, depending which way you turn it. Make sure you jack the front up so the tires are off the ground. You can do just one tire off the ground at a time. You may not get the amount of lift you want at first, drive it a bit to let the suspension settle. Make sure the both side are even. After you are happy, get an alignment as soon as possible.

Oh, and has been mentioned above, plan on doing some cutting/grinding.