[Livrat]

Tony first of all I would like to welcome you to the board,
Sorry to say but none of the holes line up.. The way I usually do it is, Cut off the donor truck frame rails just behind the shock mounts.. then take each frame rail and cut them where they bend so you have three flat pieces, A top, A side, and a bottom.. then use those for templates, You will find some common holes that will line up.. bolt each piece on top of the Blazer frame rails and use "transfer Punches" to center punch all of the needed crossmember holes and start drilling, start with a small bit and work your way up to the desired diameter.. I hope that was not to confusing,
For the rear end the most inexpensive and easiest way is to go purchase some new spring perches and put your rear end on top of the springs, You will have to change the shock location as they will be at too much of an angle to actually work correctly, you do need to make sure the "pinion angle is correct or you will have a vibration and it will eat u-joints,
A 4 bar and an air bag setup is an awesome way to go, just more fabrication and money.
If you would like to know more feel free to give me a call
Mark
206-406-2719