[240RR]

OK....I am using rear suspension from a 350Z and need to figure out how Nissan or OEM measures track width. I always thought it was flange to flange (outside) but appears it may be a center of the tire measurement.
If I can not find out without a doubt I may have to hijack a 350z and get some measurements as this is critical to my chassis build.
OEM specs state rear track width on a 350z as 1539mm
Thanks!