Overheating issues

All this is alien to me. I run a 13LB cap on my 75 F250. I have an overflow tank, but the hose going to it from the radiator rotted a hole in it a while back and I've never replaced it. Even still, the radiator never vents out of the cap. Never. Not even in the hottest of the summer. You simply cannot fill the radiator sloppin full. You must leave an inch or two between the coolant level and the top of the tank to act as an "expansion area" and you will likely never even need an overflow tank. I'm still gonna replace that hose whenever I finally think about it.