Given that M3WServices and Phil Bleazey have a supply of X Wedges, I suspect there is no need to rush to a different engine. More likely some machine shop will engineer new pushrods, valves, cylinders etc for the X-Wedge (until it be comes the Ex-Wedge). See Cameron Engineering for the latest in JAP engine technology for M3W 2 and 3 speeds for example...
If you really wanted a different engine I think the
Blackburne would be an interesting project. Perhaps the G56 folks might want to give it a go?
