the alternators are destroyed by the heat from the turbo and engine harmonics
the 4x4 had a heat shield fitted to the back
the 909 alternator has metalastic bushes to insulate it from the engines harmonics
plenty of production cars have this type of alternator you can use
You can also use a heat shield off some audi models that have a ducting pipe
remember the alternator air intake is from the rear and is drawn through the front by the fan
very common problem you have with the std alternator on a 2wd your climate won't help