2002 ram quad cab4x4 with a 4.7 L auto tranny what should the rpm,s be at when taking off at a street light when driving normally mine is at 2000-2500rpm is that normal ?

that is doing the speed limit in a city wich is 50km per hr

That sounds high to me. 50km/hr (30 mph) may be too slow to set the OD. The RPM's also depends on your rear end gears.

the rear end gears are factory

Sometimes manufacturers will put lower gears in towing packages or sport models. It gives better performance.

ya mine has the towing package on it