Thanks guys, at least I know that the HiAce diff is out the equation. Its a bugger when lack of money handicaps ideas. I might measure a cortina diff as the 250ci version had the 2.77:1 ratio as the falcon . The only problem with this diff is the axles are 4 bolt instead 5. The hassles are many but the old Commuter is much nicer to drive with 4.1ltr instead of the old 2ltr 3Y.