I've lifted mine, bit by bit about 4".
Once you have the parabolics, which will raise about an inch from stock height, then you can fit some 33" tires (255/85R16 is what I have), which adds another inch and a half or so, of course depending on what you had before. If you were running 28" street tires, you'll see even more lift. Only thing is, you should find some offset rims as the stock 88" and 109" rims are set too far inboard and will cause tire rub on the frame when you mount big tires. I'm using some aftermarket Defender steel wheels, but either stock Defender wheels or Wolf wheels will do the job.
Beyond this, it gets a little complicated...
I took my parabolics off this spring and brought them to a local suspension shop. They dismantled them, re-arced them to a higher degree and reassembled them, adding teflon pucks between the contact points. This added about 1.5 inches to the height. This cost me a grand total of $142 including taxes, so I'd suggest it to anyone with parabolics, maybe even before you install them the first time.
I also did a frame replacement earlier this year due to my old frame simply being rusted out. Before putting the new frame under the truck, I extended the spring hangers by about 1.5". This was a lot of work, but I think now looking back it was worthwhile. I also added a similar length to the shackles, because if you do one without the other you only get half the lift of doing both.
All totalled, after everything settled in, I'm about 4" higher than where I started.
Details of the frame swap and height increase can be found on my personal blog by clicking the signiture graphic below. Go back to November December 2004 and start reading from there.
Dave
