Burgie; Hang in,If I,m not mistaken the ONLY thing that changed on the GVW was the AXLE SIZE/RATINGS i.e. springs, NOT the steering boxes. In other words a C60 is a C60
I have a few Mid 60,s Motors books in the garage it,s just a prob gettin there right now
Regards Steve sr.PS I,d be willing to BET that the box in the 66 has the same part# as the 64
