normal temps on the gauge is when the needle is at about the half way mark...lately when driving around town the needle goes to the 3/4 mark and stays there..it also does the same thing when driving 60mph or more, but when I drive the vehicle at the slower speed of 45-50mph it goes back down to the 1/2 mark...also when idleing for a short time in the sun the needle is at the upper limit but when I move the car into the shade the needle goes down to the 1/2 mark again for a minute or two...I have installed a new thermostate and checked the coolant for the proper strength and all is fine...I suspect that I need a new Rad..not sure ..any ideas

Yep, sounds like your radiator has become clogged. You can go new or pull the tank off one end and use a stiff wire or piece of sheetmetal 3/16" wide x .040" thick to clean out the passages, then carefully reassemble with a thin coat of RTV on the gasket. Let it cure 24hrs and give it a try.