Also check out www.vwdieselparts.com
and www.vwdiesel.net with forums in both French / canadian and English

They both have a wealth of information on IDIs, both turbo and normally aspirated as well as TDIs. There are also forums for bio-fuels, parts and cars buy/sell, performance mods, etc.

I just sold my '91 1.6 NA. Bought it with 275k on, ran it up to 315k. Always got 43+mpg, and had just replaced the exhaust w/ a 2 1/2" system, Koni's, H&Rs. Sold it for quite a bit more than purchase price, though I put a ton of work into it.

It financed my '95 E300D, and I couldn't be happier..
Between that and the '79 240 4-speed, I have all I'm liable to need