Read through this. look at my post #8 this is a pic of a 65 housing . this is the bottom of pinion snout. note K (nov) day and 4 year of cast . you can re-stamp code. but this housing had the 64 letter style code for ratio/type stamp style . dont know if this was a anomaly for that date of cast .
http://forums.maxperformanceinc.com/...housing&page=4