[suicideneil]

Easy.

1) UE ultralite diff with 6 or 8 spider gears, or just use the case and get ofna 1/8 scale inards.
2) FLM hybrid bulks and use the ofna or hotbodies inards again (buggy, rather than truggy gears).
3) Modify some Muggy or LST2 diffs to fit.

You can find a how-to in my Emaxx FAQ (scroll down, you'll see it).