every single part swaps over onto the 2.1 long block.

it won't be quite as good as a 2.1 with 2.1 exhaust system and 2.1
intake on it would be,
but it'll work.

one reason to use the 2.1 exhaust is then you can have a 2.1 oil
cooler/heat exchanger on it . ( which can be interfaced with the 1.9
cooling system )
there are quite a few parts to the 2.1 exhaust system though ..
perhaps 10 parts ..
including the rear aluminum rubber engine mount carrier ..
it has holes in it for 2.1 muffler support brackets.
if you could get all those parts 'good used' it wouldn't be too bad
..cost wise.
new though ...
it would be a lot of bucks for sure.
You can also upgrade all that later too.

the 1.9 exhaust system, muffler, and bracketry  is rather mickey mouse
compared to the 2.1 system actually.

it's nice to upgrade to a  heated oxygen sensor too.

have fun !
scott
turbovans

On 5/12/2012 9:46 AM, Paul wrote:
> I'm considering putting a 2.1 under the lid where my 1.9 currently resides.
> My question is what stuff is interchangeable, if any, or do I need to get
> things like all new exhaust and what about the cooling system, wiring
> harness etc. Any insight would be greatly appreciated. Time is running out
> for my 1.9 and I would hate to have to deal a catastrophic breakdown on
> some highway, or lowway for that matter.
> TIA,
> Pablo
> 85 Westy
>