Sorry,I thought you said a mech was doing the Quaife but what ever.You will need a set of Ford shims for the diff, around $120 a set.You need to measure the Quaife with its new bearings on ,new outers in the case and a 1.00 mm 'base' shim from the 'pack' then you can establish if a custom shim or m/c is needed re the Ford specs...
