As I know TRD springs are produced by Eibach, arenīt they?!
Andrew, I think its one of them! Either Eibach or H+R!
EDIT:
hereīs the link to a site of a Toyota brochure i posted some time ago (post #1061, couldnīt tag it)!
http://www.ft86club.com/forums/showt...ion#post172637