This subject has been discussed from time to time.  Here's a tidbit pulled
from a Dec 2007 post I made:

The size of the larger inlet hose is 11mm (VW N 020 300 1).  I have used
standard 7/16" fuel hose from a FLAPS, but this uncommon hose isn't really
easy to find.  I have gotten away with using 12mm Cloth Braided
Emissions/Vapor Hose (VW N 020 374 1) as the barbs on my pump and the
pre-filter pretty well accomodate the hose and because there is no pressure
to deal with should be quite safe.  Always use clamps of course. This is
what I've run for the past 10 years now.

Now a bonus for you (& other list members) if you choose to use the factory
style square plastic pre-filter like I do on both my 84s:

VW:  133 133 511
Bosch Short: 71013
Bosch Long: 0450901005
Wix: 33274
Fram: G3743

I change my plastic filter every oil change to prevent fuel pump
starvation.  They're not expensive and it goes a long way to keeping your
fuel system clean.

Additional Info:

Some Vanagons thru the late 80s were equipped with with BOTH the square
plastic filter and the metal cannister (Bosch 0450 905 030).  Both my 84s
have this arrangement as original. The metal cannister filter has 8mm barbed
fittings on both the inlet and the outlet and is mounted on the "pressure"
side of the fuel pump.

I replace the metal cannister filter once a year.

YMMV
--
Jim Thompson
84 GL 1.9 "Gloria"
84 Westfalia 2.1 "Ole Putt"
72 411 Station Wagon "Pug"
oldvolkshome@gmail.com
http://www.oldvolkshome.com
jim@airheadparts.com
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On Tue, Dec 30, 2008 at 1:09 PM, Tony Collins <tonycollin@gmail.com> wrote:

> So it is time to do that part of the fuel line.... I like to replace the
> fuel filter while I do this, but I keep getting wto times of filter.
> One is plastic and square, it looks like the inlet and outlet sides are
> diferent diamters. The other is metal and more like I thought the filter
> should look like from dealing with other FI VW's.
>
> Can some one point me in the right direction?
>
> Thanks,
> T.
> --
> 82 Scirocco "Rodolfo"
> 85 Vanagon "Blubrik, El Guapo"