Originally Posted by barry123400

The radiator you sourced was brand new? Two engines acting exactly the same raises questions unless as mentioned your experience is normal and typical on these.

You can wire in a switch to separatly manually activate the electric fan system. Especially if there is no normal temperature switch that does it when you think it should.

You have a clutch fan and should also check that it is in tip top condition. They are and where a wear item on each of the engines.

Since you did change out engines the fan shroud is present now? Verification of the dash temperature gauge may not be a bad ideal as well. Even though it is probably overkill to do it.

If your fuel milage is lower than normal check for a dragging caliper or two as well. This could make the engine work harder than it should have to. Just feel the temperature of all the wheels after a run for sameness of temperature with your hand or a laser temperature reader. This is how I determine if a caliper needs attention if it is not obvious.