So limited to 15" means max 12.19" discs, suggest min of 1.25" thick, unless you want to get real ambitious and go 1.375", but I see little need unless the autobahn begins installing a lot of red lights. Since clearances are tight be sure you take into account your particular wheel if you go 12.19", which is a common size. Wlllwood offers a large cost effective selective, did you mention the amount of daily poor weather driving exposure, since most, not all of the wilwood stuff lacks caliper weather protection. I also would work out the front conversion, test and then decide if rear discs are really needed.

Last edited by jcc; 10/14/13 10:16 AM.
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.