does anyone know the diffrences in spring rates and sway bar diameters between the standard equipment and the r- package stuff, i am looking into buying a used set of r-package struts, springs and sway bars and need to know if it is worth it. On another note, what years of miatas came with air conditioning and manual steering, i am going to manual steering but want to keep the a/c till it fails if i can find an idler/tensioner pulley to replace the p/s pump.