Go with the 87c thermostat.  This way the engine will run at the proper
temperature for the ECU Temp Sensor to send the best signal for proper fuel
mileage and power.  The 80c is fine, I ran one for 5 years on my 84 (with
the 2.1 engine), but I found that after changing back to an 87c a few years
ago, my mileage got slightly better and the tailpipe was a lot cleaner
(relatively speaking) in the long run.  Heater felt more efficient
in keeping me warm too.  The 80c is probably best for areas that experience
high ambient temps most the year around.

And yes, do change the thermostat - you should whenever changing out the
water pump, it's just plain common sense.
--
Jim Thompson
84 Westfalia 2.1 "Ole Putt"
73 K Ghia Coupe "Denise"
72 411 Station Wagon "Pug"
oldvolkshome@gmail.com
http://www.oldvolkshome.com
**********************************
On 12/15/06, Kevin Jessee <kjessee@katewwdb.com> wrote:
>
> I recently found that my 91 was running like a pos.  I replaced the plugs,
> did a tune up, replaced the tail pipe that had a small hole in it,
> replaced
> any sensors I thought might be the/a problem.  I ended up finally knocking
> out the Catalytic converter after reading up online.  It made all the
> difference in the world, at least till now.  Yesterday my 16 y.o. daughter
> was driving it to school and noticed it was hot.  Luckily, I was home and
> she called me  from 5 minutes out.  I dashed over to find that the water
> pump died and was shooting straight out the blow hole thingy(?).  I think
> I'll do it myself since the locals want 460 to get r done.  I will also do
> the thermostat.  Question is, should I go with the 87 degree one or the
> cooler (80 I think) one.
>