I lowered my rear
I did mine a few months ago, '00 reg cab LWB 2wd. The dang thing set 5" higher in the back and it rode rough, I was fixing to get rid of it.
Finally sucked it up one night and started at it. Here is what I did:
First jacked it up from the bumper and let the suspension hang freely. Took of the rear tires, used a small 2 ton jack for under pumpkin for letting the suspension up and down. Pulled out the top overload leaf packs after I inzipped the u-bolts. Had to loosen the tank on the driver side to pull the main leafs out.
You can do ine of two things reguarding the clearance with the top overloads hitting the frame mounted bump stops.
1. Either, pull the main springs apart, pull the second from bottom leaf, remove all the little metal spacers. Then pull the overloads apart and bolt all the springs back together with the main leaf bolt (just long enough too)
2. Or, pull the main springs apart, pull the second from bottom leaf, bolt it back together and put it all back on. You will have to still use the 1" spacer that seperates the two leaf packs and then just pull the overload frame-mounted stops off until you get ready for a good load.
If you do #1, you will not use the spacer that seperates the two leaf packs, because you bolted all of them together. The main thing is to take the next to the bottom leaf out of the main spring pack. This will give you a 1 3/4" drop.
Another thing is you can, of course, pull the 1" block that is on bottom of the springs and it will give you another 1" additional.
I pulled the 1" block and did #1 above (now recommend #2), but either way you will get 2 3/4" drop from it.
1 more thing I had to do, I had to pull the rear brake adjustment arm off the driver side rear axle. It determines rear brake pressure depending on amount of load you have (squat). I had to pull the arm off and cut it 3/4" I think and weld it back together. Took only 20 minutes.
Over 12K miles later, never have had a problem, truck sets a WHOLE LOT better and it still has a nice little rake to it. Also the truck rides 100 times better.
I think it took me a total of about 3 hours or so, #2 that I mentioned above will be quicker and better I believe. One day I will go back and redo it. If you did it my way, you will need some spacers for the bottom of the u-bolts so you don't run out of threads.
Let me know if you have any more questions,
JD