You need to remember or know that all late model Mopars with throttle cables can have the throttle cable adjusted to limit the power by not opening the carb. all the way on the throttle cable holder on the engine
If he is a hot rodder or likes speed do it now, limit the throttle opening, for a while so he doesn't get hurt or in more trouble than he can handle now so he won't know how much power can be had later
Good luck either way