Any engine conversion is a compilation of a few big items and hundreds
of small details.  The big items might cost more money, but it is the
details that make or break the final product. The learning curve is not
steep.  You need to do 8-10 to start getting it right, and then go back and
redo those 8-10.
    A do it yourself engine conversion can be a very rewarding project if
you are up for a project.  If you are in a hurry to get your rig back on the
road, it is a painfull path to take.
    A turn key kit allows a home mechanic or local Garage to get into the
engine conversion biz pretty painlessly.
    We have worked on a few conversions done by individual shops and
do-it-yourselfers.  Each was a nightmare.  I just spent 8 hours pulling a
EJ22 out of a Syncro.  Yeah 8 hours.  It normally takes me longer to drain
the fluids than to pull a 4 cylinder Subie. We have also seen some
beautifully done conversions by do it yourselfers.  They didn't come to our
shop because they worked perfectly.
    I think the lessoned learned is if you want to do a conversion yourself,
it is best to buy some of the parts/systems from an established vendor to
keep yourself from reinventing the wheel, unless reinventing the wheel is
something you like to do (sounds like a British hobby, like train spotting!).
    Bostigs core conversion parts will allow any decent home mechanic to
install a Zetec, and the Subie path to Vanagon conversiondom has several
reputable vendors.
    The average time for a newbie to do a Subaru conversion is 4 months to a
year.  A turn key kit can be installed in 1 - 3 days.  Buying a few proven
parts/systems can take the 6 month project down to a few weeks, and yield a
much better result.

    John
    East Coast Vanagon