i have a 99 mustang. it has a 7.5. i am building a 8.8 from a 96GT. it has a spool and i am using my factory disc brakes. i am installing moser 9" housing ends (PN7700) specifically designed for the 86-04 mustangs. my machinist is telling me that he needs to know the axle flange to housing flange offset. is this a common spec (as in can someone tell what it is or where to find it) or do i have to tear down my brakes and stuff and measure it myself. he told me to remove the brakes, remove the axle, remove the backing plate, re-install the axle, measure the difference between the to flanges and give him that number. he also said he needs the overall housing length from rotor to rotor. he is custom making a set of 9" axles for me, 33 spline, he is charging $100 labor for installing the 9" ends and stitch welding the axle tubes to the housing. and then he quoted me $350 for the axles, bearings, and plates. does this seem like a fair price?