What I see with customer cars typical heat issues

timing retarded not correct
electric fans--they BLOCk air and are not needed
no fan shroud--fan at wrong depth in shroud--
no wire in bottom hose causing it to close up
crusty radiator--one fresh back from the shop may be new paint and "rodded out" but in no way has the capacity it once did

I never see bad gauge, pumps ( as long as they don't leak) , or jetting off enough to cause issues

It is always the basics done totally wrong