Truck Repair: truck running hot, radiator core, rubber gasket


Question
i have a 1987 ntc 350 cummins with a low flow cooling system recently truck start running hot, as if no water is circulating through the engine but radiator is still cold this happens about 5 miles down the road sometimes less ,replaced thermastats as well as radiator core just last week, a new water pump 3/16/06 any info you give would be valuable. thank you

Answer
I would verify it was the correct water pump.Any work doen to engine prior to this problem?There are special water manifold rubber gasket with restrictors to slow the flow down.The thermostats look the same but are not.They are engraved with BYP & RAD for which one goes where and arrows on the housing showing which is in & out.