Concerning switch to synthetic oil:
I think it's very good.
I think it's better to just use synthetic oil and not to flush the engine.
You can
change the oil and filter again after a couple of thousand miles to clean
out any dirt that might accumulate in the filter.
I did this on my westy a couple of years back. It had 60,0000 miles when
I switched to synthetic oil.  The car seems to like it. I have done the
same
with another much older car, and have since put on another 70,000 miles,
and
it still runs great. I change the oil at least every 5,000 miles even with
synthetic.
Harald
'90 westy
----------
> From: Barbara Sutton <bsutton@UOREGON.EDU>
> To: Vanagon@GERRY.SDSC.EDU
> Subject: Re: Synthetic Oil(s)
> Date: Thursday, October 09, 1997 11:03 PM
>
> mdstockr wrote:
>
>
> >   - You should not use in an engine with more than 24,000 mi that had
previously used
> >     conventional oils, unless the engine is flushed first
>
> Wow! Can anyone else verify this? I just switched from conventional to
> Castrol 20-50 synthetic in my Westie (55,000 miles) and didn't flush the
> engine, just let it drain for two hours and changed the filter. Is this
> bad?
> Thanks,
> Cris.
> Eugene, OR.
> '91 Westie "Fafner"
> '66 Standard
> '67 Deluxe (parts bus)