I run a double shackle set up. I just made another set of shackles and attached them to the factory ones. the double shackle works well, allows for lots of drop. I also cut out my old front hangers.

1988 SR5 x-cab 4x4 w/22-re -mod's- custom cold air intake, red top optima, lo-pro bump stops, thorley header, high flow cat, 2.5 exhaust, dynomax muff, chevy springs, procomp shocks .....