1996 dodge ram running hot

my 1996 dodge ram,360 100,000miles keeps running hot. It is'nt losing any water,the fan clutch,thermostat,radiator,waterpump are all new. there is pressure on the top hose when the thermostat opens. the heater blows hot air when the heat hand is up. it will get as hot as about 240 degrees.am at my wits end. any help appreciated.

Check the catalytic converter may be blocked.

Also, have someone physically check the temp with a Raytek laser pyrometer, and see what exactly is the temp of the coolant. If you are leaking water externally, it could be as small as a bad temp sensor. Also, check out the insides of the motor, check your oil and see if it's not light brown like cappucino or something light, that means you have a bad head gasket and it's leaking internally.

o.k. I think it's fixed.thanks to all the useful info. I parked the truck with the front elevated,took of the rad.cap,and cranked it up,let thermostat open and close no air bubbles. the next morning I started to put the cap back on,about a cup low of water. I put the cap back on cranked it up,let the thermostat open,squeezed the bottom radiator hose and the top hose moved around. no circulation . brand new(6 month old) high performance water pump wouldnot perform. replaced it with another one(lifetime warranty)and all is well,so far. thanks for the help and look forward to helping.