I am having trouble figuring out a way to run the factory 370z springs on a coilover with a lower spring perch meant for 2.5" springs. The z has 3 inch lower spring increasing to a 3 3/8 upper. If i knew someone that could fabricate a cup with a 2.5 inch inner diameter or create a threaded perch with the the larger spring in mind. I could run a big washer but would have to find someway to keep the lower spring isolated.
link to what the factory setup looks like
09 Nissan 370Z RH Passenger Front Strut Shock Spring Assy 56110 1EAOC 7033 | eBay