with all this talk of r31 struts i thought id go investigate the ones that i had

found out that they bolt onto stanza steering arms as you can see
but the r31 steering arm is alot like a bluebird one, much like the rest or the strut

if i could get to the bluebird struts i have i would take some measurements, but the calipers attatch the same way, bolts into the caliper rather than the strut like stanza
therefore the disc is offset a fair way out the same as bluebird
and from memory the bluebird struts have the same caliper bolt spacing of 90mm
also standard r31 discs are intergrated into the hub, will check one day if bluebird hubs fit on