Radiator tips for 67 Dart with 440

Thank you everyone for all of your input and advice on what to try.
I ended up getting a new radiator with fan/shroud. Went with proform and got one of their slimfit direct fits for a-bodies with a 2200 cfm cooling fan. IT WORKED!
While I did that, I also took the water pump housing off and checked that over. That was all clear and looking good so I have her a fresh coat of orange and re sealed the whole works. In total it all took roughly 3 hours to take out rad, remove housing, paint, regasket, install new rad, reinstall water pump and housing, hook up hoses, and roughly an hour to get the wires hooked up and the fan running.
With a 180 stat it will sit right at the 190-200 temp city driving.....

The next issue... while going highway speeds (55 @2700) the temp will slowly creep up to 220 and will continue until either stopped or slow down for reduced city speeds. Bottom rad hose has a spring, but top hose is normal. Could top hose be collapsing and causing it? I purged the cooling system so to my knowledge I have all the air out of the system (will try again next time I work on the dart) was also told to look into an aluminum water pump housing since they disperse heat easier and faster than the factory ones. 20220514_094141~2.jpg Snapchat-1496278684.jpg