Custom, hahaha. Going to aim for a high spring rate to match the stiff front and a 3" inward relocation of the leafs. Haven't decided on whether to go with steel springs or composite yet. I'd imagine a custom set of composites are more pricey than steel leafs, but I'd need to confirm that. Need to figure out how to translate wheel rates and leaf locations to spring rates. Also need to try and figure out the proper amount of free arch for a car that will end up with a heavy 1.75x.12 cage.