I first ran a cut through the hanger shackle flip before figuring out my bolt on bracket and its still cut up to this day. Most people go with a shackle flip to soften the ride as well as get rid of the lift blocks which through leverage will exaggerate axle wrap. Getting rid of the blocks does not eliminate wrap up but does offer more resistance to it. The cut through the hanger method can get you up to 4" of lift but usually much less due to spring fatigue which is why people suggest running a longer shackle to help make up the difference. Keep in mind that 2" of additional shackle length will only equal 1" of lift at the axle. Getting a shackle that is too long can also play havoc on your rear end geometry. Once you flip the shackle, its arc of motion when loaded up will cause the back end to sit lower than before with the same amount of weight. So even with a 2" longer shackle on your stock leaf packs (putting you at 4"-5” lift), any weight you add will cause the back end to settle down quickly usually about 1 ½” on a blazer (full of gas, spare tire, trail gear, etc). The cut through the hanger style mod, while achieving the flip, requires quite a bit of material to be removed from the bottom of the hanger to allow a full unrestricted range of motion for the shackle. You’ll find that many people end up plating the top side of the hanger (where the shackle used to slide in) with ¼” steel for support and removing the rest of the bottom in order to achieve this without sacrificing strength. This is not a bad way to go if you have the tools and elbow grease to put into it, and the resulting lift fits your needs. As for driveline geometry, any shackle flip you perform whether home brewed or purchased is going to require pinion correction unless your adding a CV style shaft at the same time. This doesn’t mean you wont need driveline correction but its close enough to the proper geometry on blazers that many don’t. Hope this helps.