Sound to me your running HOT. Check for crud on radiator. Is fan belt tight and good. I installed a window screen on grill on Ford 600. Some still gets thru like dandelion fizzies. Need to stop and clean off both radiator and grill. The only problem not solved is the weed seed entrance at the bottom of grill and radiator space. Have thought of stuffing some fiberglass insulation in that void for a temporary screen. this is a issue in all most all older Fords.
Charles Krammin SW MI