Its simple right? Well it can be, without spending much money. There are some reason you would want to do this, like if your local track has 2wd stadium truck on-road or something like that. Or maybe you cant afford an on-road car and you want to go on-road with your off-road. Whatever the reason I will show you how its done!

THIS TO THIS

Well sorta, Not quite that much of a on-roader

First, I think you should get your suspension worked out. Its almost thee most important change. You must lower your suspension arms drastically, like 1/4 off the ground or less! Then put much thicker oil in the shocks or if you must just make the springs tight. Try like 50 wt - 90 wt shock oil depending on the weight and stuff. You can also buy stiffer springs. Put the shocks on the holes farthest from each other to lower the ground clearance and center of gravity.

Second, get on-road type tires. For 2.2 rims there are lots of options like pro-line road hawgs or speed hawgs or duratrax slicks or something. I suggest getting another set of 4 rims so you can change back and forth from on-road to off-road very easily. Or if your really one a budget use some old tires you have and grind them down so there slicks!

Now really that's about all you need. You could try to retro fit a touring car body on there if you want but it probably wouldn't work. Also you can gear higher now with the probably smaller tires.

Now you have a great off-road and on-road truck in one! Remember you can always convert off-road to on-road but hardly ever can you convert on-road to off-road. Rally maybe but it wont work that great.