Cooling question

[mtully79]

I recently took out my radiator and replaced it with a 3 row aluminum. I also added (2) 12" fans that came in a kit with a control and relay that kicks on at 185 and turns off at 170. I took out my 180 degree thermostat and replaced it with a 160 to run with the controller/relay set up. At idle it worked peachy, coming on and cutting off consistently, I took it on the highway for 20 mins and when I parked it the fans kicked on as usual, but wouldn't cut off as the engine temp didn't drop low enough.

My question is do these 350s run hot? I spoke with the radiator company and they assured me the setup was right for my truck, but I'm wondering if I need to go with a larger fan? Plan this weekend is to plug in a temp gauge and see what's actually happening with the temps when the controller asks for the fans to cut on and off. Has anyone seen a similar issue?