Volks,
Just want to share some information with those interested in this topic.
I just finished installing Four 4" JBL GTO 402 speakers in my 90 Westy
Syncro.
Sounds great with my new Sony XR-1750 radio/cassette deck.

The only alteration to the van I had to do to install the speaker was to
remove about 1/2 inch of the gray rubber wood trim (no plywood) nearest the
rear passenger side speaker. This speaker is mounted in the A/C box. Even
the original speaker screw holes matched up!! And what's better is that
Crutchfield is NOW having a close out sale on these speakers. They list them
in the catalogue for 79.00 a pair... 59.00 on sale now... And I got mine for
49.00 a pair because they were returns (Crutchfield assured me that they
hook up with power and test their returned speakers.) So I got Four speaker
upgrades for $100.00.

The only other alteration I had to do was to widen the screw holes in the
plastic face plates about 1/16 of an inch each with a file... easy. The
front speakers BARELY fit between the door panel and the side of the dash...
have to make sure you push the grills as deeply into the face plate as
possible. The face plates are a little larger and stick out from the surface
further so I don't know if these speakers would work if you have manual
windows (room for roll up handle?). I have electric windows so not a problem
for me.

Anyway, I'm happy with my new sounds... The Crutchfield number is
800-955-3000 7 days a week.

Bill
90 Westy Syncro