The diameter of the drive sproket is quite a bit smaller than the dia. of the front tire, so I would think the t-case ratio would be too far off for any other than stock replacement. If you're not planning any serious mud runs or hill climbs, I don't think track drive only would be a problem. I know the purists will be on a rant, but it's yours and you should be able to do what you want. Way better than on a scrap ship to china!
By the way, the t-case and trans are a single unit. If yours works out, I have a junk M3 out back that I might try something similar with. Too many projects, not enough time!
