Check out ShaunB's build up, WHITE_TRASH used some 79 caddy seville springs with some other chevy springs, Probly one of the best setups I've seen, he got 4"-5" lift with no blocks, do a search on "caddy" you'll see what I'm talking about.
I have allpoo's right now and they are way to stiff, so I am going to pick up either the F-150's or the caddy's if I can find a set or two.
Late
Joe