Here's a link to some adapters that might help you out
http://maximizerproducts.com/mtr.html
I know some people don't advocate the use of adapters for maxx size wheels on the CEN but if you stick to a low profile pin tire it shouldn't have that much more mass than a stock MT2 tire. On CEN's race truck I read somewhere that they cut out the center of a stock wheel and put it in a maxx wheel so they could use larger tires. That is alot more complicated than using adapters.
rolland