Buda, this is what you are talking about (pic)
You take the clamp off the bottom of the strut, cut a 1/4" 45 degree bevel all the way around the bottom of it, then weld a small metal tab (important) on the top where the strut's locating tab rests. The locating hole strut where the bolt goes through is oval shaped, and there is not enough material to drill a new hole, so you have to use a file to make the hole longer.
Depending on how much lift you already have and the angle of your upper and lower control arms, you will gain anywhere from 1/2" to 1" of lift. I have RC spacers + 1/4" rustys type spacers (fabricated). When I added this, I gained another 3/4" of lift from a 3/16" lift here.
The further the control arms get from horizontal, the more lift you will get from adding length to the strut assembly. 1/4" at the strut assembly does not alawys = 1/2" at the wheel. If the LCA is horizontal, then 1/4" at the strut assembly = 1/2" at the wheel, but if the LCA is at about 25 degrees past horizontal, then 1/4" longer strut will = closer to 1" at the wheel.
2005 WK 5.7L Hemi, RC 2" BB + fabrication = 3.5" lift, JK Rubicon Tires & Wheels, 1.25" Spacers, Fabricated Skidplate, Fabricated Recovery Points, Airaid CAI, Superchips, HIDs RED WK Club #10