We recently dropped our two-door '00 Blazer with a Belltech 4/5 drop kit, and the bottoming out just plain sucked. Notching the frame should have been done the same day the drop kit was installed, but being in a rush, we slammed it and started cruising it immediately. Luckily the Thorbecke Bros notch kit is straight forward enough to install in an afternoon.
Follow along the few steps on this page and add 2¼ more inches of axle travel today! Bottom out less. Experience less banging. Save yourself major headaches and Tourette Syndrome-like swearing fits.
Tip: when ordering, select the "crooked frame" if your Blazer/Jimmy is a two-door model. '95-plus four-door models require the "straight frame" notch.