My 02 dodge ram 1500 {4.7L engine} began overheating. Ichnaged my thermostat but overheatiing continues. Is there anything else I could check before I replace the water pump?:confused:

Why would you think it is the water pump? Is it leaking?
Personally I would when cold remove the radiator cap and check two things. One is it full of coolant, and two, what does the radiator look like. If it is all crudy, then it needs a radiator flush. Did you install the correct thermostat?