Are you refering to rancho 44044 springs (4'' lift full size wagoner/cheorkee) ? It was a common mod and still done from time to time. I helped this local guy put them under his taco, they work well ,but I think his truck ended up kinda tall. If you are wanting to lift your truck useing junk yard parts then just use hybrid rear springs.
If you are gonna buy springs check out marlins springs. I hope ya got enough dough for a quality crossover steering system, I run marlins hysteer kit and love it.