Hi-tech as well as futaba servos will fit with no mods at all... The only thing that might be different is the steering arm... The new servo will come with an adaptor if needed..... I don't think yoy will need it........The difference is absolutely amazing.... Gone is the sluggish steering and planning ahead... just crank the steering and turn... Wait till you do your 1st donuts...... Just so you know... The steering is slower when the truck is not moving...