Rear lowering questions and advice

[Ice&burban]

I have 90 Burban. I'm getting 2 1/2 drop spindles from guy he had on his for about six months. He had his low with springs and flip. I don't want to go that low (roads suck around here).I've been searching like crazy trying figure out what to do.
The front spindles and like an inch off the coils should give me 3 1/2 up front. The back I would like to go 4".
One thing I read somewhere and now I can't find it. Flipping the rear and putting in a lift shackle. Is this something that someone has done? Also, I've heard of a lowering shackle and taking out a leaf or two. Only thing, I tow every once in a great while. Maybe once a year. Even thought if I went the route of taking a leaf out, to add rear helper bags for towing.
I'm open to any advice on what is a good way to lower the rear around four inches. If you have pics of what you did to rear as well would be great.