As long as the tyre centerline does not move, the scrub radius stays the same. On my previous Morgan I changed from the original wires to Dayton wires of the same width, but with 5mm more offset. This gave the car a little narrower track. Of course the tyres also were changed so it is hard to tell what made the car feel different, but it became less nervous at the cost of a little less aggressive turn in.
I don't know if the proposed change of offset on a Morgan is OK, but I guess people in the racing community should know. For more details, see the Honda tuning magazine
article on offset.
Harald
