the mechanic didnt ask me for any specs, i was just trying to gather the info before i went over there. and he is helping me do the install on trade, im not dropping them off and paying for the work. he's accually a diesel mechanic, with only limited experience doing rear ends, thats why i wanted to bring as much info to the table as possible. his buddy that sets up gears for a living is coming over to make sure everything looks good before we button it all up. if i wanted to pay 700 bucks i would go to the local drivtrain shop. and your right, if they asked me for the measurments i would go elsewhere.