crazyhole,
Do a search on 208's here and you'll get plenty of info... They are commonly swapped out for all iron cases, but in many cases have served their owners well. The rear slip yoke can be troublesome, and they crack like an egg if hit by a rock. Again on the good side, they have a "lower" low range than the 205. Just like everything - plusses and minuses.
Oh... and nobody makes lower gears for the 208.
Marv