Does anyone think it is the radiator besides me?

Sounds like a partially blocked radiator to me. A partially blocked radiator will cause temps to rise at higher speeds because although you have more air flow accross the fins the water isn't flowing through the whole radiator & thus acts like it has too small of a radiator in it. Fine at slower speed but more rpm= more heat & a need for more capacity to cool. Have it professionally cleaned out or replace it with a known good radiator. Good luck.