Even box stock new 4907 maxx trucks don't have a strong enough servo to turn the tires with the truck sitting still on the ground.
As long as it's not struggling to turn the tires when moving your good.
If it does have a hard time steering while moving & the front end is not binding then get your self a 250oz or better MetalGeared servo & call it a day.
Servo's are the one place were you get what you pay for.