You really need to offer more information to get some good advice.  Why do you need to overhaul the top end? What are the symptoms? What is the mileage on the engine and has it been serviced before? Are the piston/ring issues or just valves and gaskets? What condition are the heads in? There are many variables. 
I for one like to do a 2.1 upgrade when available and cost effective. Getting a fairly complete one with exhaust is a deal clincher.  1.9 exhaust is becoming difficult to get and the early bracket system is lousy. The 2.1 exhaust is better, more readily available including stainless steel options. The 2.1 will work perfectly with the 1.9 ignition and fuel injection. The oil cooler can be grafted into either cooling system. For a real nice job upgrade the van to the 2.1 cooling system. Almost self-bleeding and works better in a number of ways. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Dan N
Sent: Monday, November 03, 2014 9:38 PM
To: vanagon@GERRY.VANAGON.COM
Subject: WBX 1.9 or 2.1... what would you do?

hi all

a 85' with WBX 1.9 need to be rebuilt or at least the top end rebuilt..

if you have a choice to have the 1.9 rebuilt or swap in for a good used 2.1...

for the same price...

what would you do?

thanks for any idea...

dan