Need help keeping the wagon running cool.

[PT Sportwagon]

Well In Aug, I took the wagon for it's maiden long voyage since I got her. I attended the Rocky Mtn GS club show and shine. It was about a 300 mile round trip.

The problem that I encountered was on the 2 lane from Laramie to Ft. Collins,CO. she ran about 190-210 degrees. I was running about 65-70mph. Once I got on the interstate heading to Denver. She climbed to 230 degrees, I was running about 75 mph. Then heading home she even ran slightly higher and I was mostly running 80. the weather however was in the upper 90s coming home. Heard Denver got to 98 that day. We made a 15-20 min stop and came out to a boil over in the surge tank and boiling in the bottom.



She really didn't cool down much on the run home until after running in the rain for about 10-15 minutes. then she got down to about 190.
I had her out just after in town and she never got above 200 in stop and go traffic. I know the gauge is correct as it is an Autometer Mechanical ultra lite. She does have a new water pump, new 180 thermostat bypass hose and housing and a new upper hose.

What could be the problem I don't like her running so hot. could I need a new radiator or mine cleaned? I would love to get her running calm, cool, and collected. Even be able to run the A/C once I get it recharged
I recently checked my antifreeze mixture and found it way off. protection down to only +10 degees. I do however need to get that better before winter sets in all the way. don't want to have any problems.

Thanks

Tim