The 4.7L also had an hydraulic fan (I think). Solenoid is part of the fan assembly so I don't think you'll be able to just replace the solenoid.

Anyway, you shouldn't be seeing any bubbles at 90/95 ºC no matter if the fan is working correctly, I've had the car at highter temps than that (near 100ºC) with no visible bubbles.

Check the expansion reservoir cap and see if it's sealing properly, better, just replace it with a new one with the correct spec. The coolant system not being pressurized will make the coolant boil at lower temperatures.

If the coolant is at correct strength of anti freeze anti boil it shouldn’t boil until around 125c so bubbles in the coolant around 90 is probably combustion gasses.