In a message dated 3/11/02 8:26:56 PM Central Standard Time,
dhaynes@OPTONLINE.NET writes

O> kay, I forgot about the intake plenum. The 2.1 and many VW 1.9 rebuilds
> need the later plenum chamber to fit on the case correctly. The throttle
> valves are interchangeable for both plenums but the later throttle has a
> larger opening for more power!
>
>

If you are upgrading an '85 to a 2.1, you might get lucky.  Mine had the
larger throttle body and air plenum already.  Also, I didn't change the water
pump and mine hooked right up.  Is there something different about an '85?  I
used the Jim Thompson procedures when I did it three years ago.

Tom
'71 Westy, '85 Westy, '91 Carat, '81 VW Diesel Pickup