I have a center-diffed twinforce, Most here know i got one from Promod. He built, it but i can see he used the lower skid plate (New era chassis, not sure if stocker has a skid plate) to hold the diff setup. I think he used an ofna dominator setup, could be the old LX buggy (51 tooth ofna geared diff) and just fastened a plate to hold the motor. for the revo shafts, thats easy.get these:
http://www3.towerhobbies.com/cgi-bin...&I=LXHFY7&P=OW
you only need the two, Cut the threads off, use the cut end with the pin in the diff with the spider and the revo shaft will fit no probs, except for maybe some cutting for length
Here is my center diffed twinforce and yes i'd recomend it for anyone, especially for short wheelbase
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Sorry my pics don't show the diff too well, but you see where it is