Ed,
I'm mainly concerned with the gear reduction. I want about a 2:1 reduction, and the 1.9:1 in the 205 is just about right. It will not be a 4WD car, and I will probably take the chain and front drive gears out, leaving me with just the gear reduction unit it's self.

I looked at the bolt on under/overdrive units, but they're way out of my price range. Used transfer cases are cheap and plentiful.

Where and why do the cases typically crack? Is it because the chain is exerting to much force, pulling the two sides together? If that is the case, I won't need to worry about it, just the strength of the gear reduction. Thanks for the info.

-Jeff