There are a lot of off-road monster trucks, stadium trucks, and truggies from multiple RC manufacturers that are fully capable of doing wheelies with no special tricks or modifications. The monstrous horsepower output of the
nitro engine provides enough torque that if you deaccelerate slightly then apply a sudden burst of speed (give it the gas -- apply more
throttle) at the right moment on the right surface it can pop those front wheels right up off the ground.
If you're having trouble doing wheelies with a nitro RC, try tightening your slipper clutch/spur gear, making sure your engine is warmed up and tuned. Don't attempt to do wheelies with a nitro RC engine before proper break-in. Some RC drivers recommend softening up the suspension so you have a little more bounce to help get the front end off the ground.