I have to agree with what has been said.  I have gone to the dark side
(Subaru conversions) and would recommend that route but only if you can do
it and fix it or their is a local mechanic that will perform the
conversion and work on it.  Unfortunatly that also applies to WBXers.  Few
local mechanics know what they are doing.
    Fixing your WBX will cost as much as simply putting in a rebuild.  I
cannot agree with this part of what was said. Spending 80% of the money to
fix 5% of the wear and tear is a giant waste of time.  Do it once and do
it right.
    I really like GoWesty, but don't know if there is enough of a
trackrecord to recommend their bigger engines.
    I think the best van engine is a Subaru, but if you cannot do it
yourself it is going to cost a lot.  If you do it yourself it costs about
the same as putting in a rebuilt WBX.

    John
    87 westy SVX