Lee,
Without going into the oil delivery differences, which I think might be irrelevant or, even, desirable, I think you are back into the issue of costly or tricky machining to reach the end. You would have to create a new worm drive and pump driven gear. I don't know if you are doing this to accomodate a 4:1 tach, but I think you could get a chronometric 2:1 from Nisonger or one of the previously mentioned UK sources easier, certainly, and maybe cheaper.
richar L.
