How about this, it came up for sale on an Aussie Mustang forum, the other day, He's asking $1500.oo
http://www.mustang.org.au/forum/index.php/topic,24234.0/topicseen.html
"For sale, Sept 1968 dated nodular housing - C4AW-B with matching 'N' caps. Has fully rebuilt Detroit Locker, new bearings...