They are one and the same now. They replaced all spring seats with the XC90 version.funny side note regarding XC90 spring seats people have been using vs. S70 OE spring seats or IPD HD Spring Seat...one of the parts folks at our local Volvo dealer told me that the XC90 spring seats are the same as the S70...perhaps he meant "same price"...I did not follow up with that question, however...perhaps someone can clarify better or knows the factory p/n#'s...
FWIW, FCP has always been great to me. They always seem to keep up a better product stock than IPD as well...usually the things I want from IPD are on back-order.