Would it be possible to set up a sportmaxx for onroad racing and if i did that is there a place around Stafford, CT where i could race it. i think that an onroad truck would be pretty cool and i want to try it.

Yes, it could be setup (consider using the Pro-Line Road Rage tires). But the competition would be slim since most truck owners race dirt.

Pro-Line Road Rage 40 Series (http://prolineracing.com/proline/tires/1104/1104.html)
Pro-Line Maxx Road Rage (http://prolineracing.com/proline/tires/1082/1082.html)

I plan on racing my truck in the dirt but i also want to be able to turn it into a killer street machine. i guess i will get a spare set of shocks and set them up for the road and throw those on when i want to race or drive on the road.

my first rc vehicle was a t-maxx . i modified it to run on road. we ran on road races at ulta racing in Hamilton Ohio twice a week for 2 seasons. The big mods we made to the trucks were cutting the springs down to have about 1/2" ground clearance. we used black springs (ultra stiff) to minimize body roll.
only four shocks to reduce weight. forward only. i dremeled the chassis to reduce weight and i took off all the plastic that was not absolutely nessecary. We used 10000 wt. silicone in the diffs. to reduce unloading of the inside wheel. our track wasn't very big so i also removed the 2 speed .my truck weighed in at 6lbs8 ozs when it was all done.