Check out the VW Engine Conversion Web site
http://frost.bbboy.net/vwengineconversionsclick here
The adaptor should cost Average price is $440 for 200mm VW, $540 for 9” (228mm) VW that is from
Kennedy Enginnering
I say go for it... It is water cooled and the power was designed for a car 2 to 3 times the weight of your car... So you can even put A/C in if you want and have power to spare. You will also get more power as the exaust will be shorter.
I am installing a Mazda RX7 13b Turbo in my 1303 project 250 to 350 hp depending on the boost.
The other thing to consider is how long you can drive between tune ups and rebuilds...
Steve from Australia has a nice set up with a water boxer if you click on his web site you can see how he set up his radatior in front.
I say go for it!