check Benny Boys site.
He did the exact thing before getting bitten by the Subaru bug.

http://www.benplace.com/

Look around, alot to be learned from this Genleman.

dylan

________________________________
From: Brendan Slevin <totorovan@GMAIL.COM>
To: vanagon@GERRY.VANAGON.COM
Sent: Monday, April 6, 2009 2:19:34 PM
Subject: 1.9 to 2.1 conversion question

So I acquired a free 2.1 that was rebuilt 30k ago to put in my 84.� I was
planning on doing the conversion the way I've read by basically putting the
1.9 WP/cooling pipes on, keeping the 2.1 plenum and using the 1.9 t-body.
What I didn't plan on was getting ALL the other bits for the 2.1, ECU,
harness, airbox, exhaust, etc.� Can I run the 2.1 ECU, t-body and airbox and
such in place of the 1.9 bits?� I know I'll be putting on a new 1.9 WP and
keeping the cooling system the same, and removing the 2.1 oil cooler.

Brendan