Overheating 360 new engine

Internal friction may well be the cause of the problem. So can rust scale on the cyl wall jackets & a host of other things.
The point is, short of building a new engine, how to control overheating?
Try the things I listed earlier. Water pump efficiency that I mentioned makes a big difference. I have dropped the temp 20* on a 1967 Pontiac by modifying the pump to make it more efficient [ capture more water & pump it through the engine ]. This is more than most as the pump design was very inefficient & Pontiac changed to a totally new design in 1969.
Bigger, 3 row radiator, will help.
Turning the pump faster [ smaller pulley ]. This is another mod that makes a noticeable difference at idle.
Better fan [ more air ].