1988 S15 Overheating

Ok heres what i have 1988 gmc s15 4x4 2.8l with 142K i drive about 32 miles to work in the morning and the truck heats up to about normal operating temp. On the way home while im still in town the truck runs at normal temp when i get outta town on the highway driving about 65 the trucks temp gague maxes out then when i slow down to about 30 in the sub division where i live the truck will start cooling down. I have replace the t-stat that didnt help.The truck runs fine so i dont think a have a head gasket problem. Does anyone think i might have a radiator problem????? Any help would be appericated .
Thank You,
Ken
:banghead: :banghead: :banghead:

Sounds like you are not getting enough flow across the radiator.
Possibly you have a clogged radiator or a water pump that is not moving the coolant through the system.
I would lean towards the radiator first.

Hi GMMerlin,
Thank you

I forgot to add the water pump was also replaced about 3000 miles ago so i will try the radiator next!! What about the fan clutch? It will spin with some resistance when its cold what about when its hot whats it suppose to do ?

Thank You,
Ken