Third Generation F-Body Message Boards - car runs better with vacuum hose disconnected from egr?

So, I was having a weird cooling problem with my car the other day. It runs about 220 on the highway which to me seems a bit high. After about 40 minutes and this happens all the time it slowly creeps up to around 230 maybe 235? Last year I redid the intake manifold, new radiator and a new thermostat and flushed the system. So I was about 3 miles from home and the temp went past 240. I got into the garage and coolant was spraying from the top of the coolant reservoir which was actually boiling. I let it sit overnight cleaned everything with hose water let it dry and started it up. there are no leaks anywhere and I find nothing wrong with the water pump. I just don't know what the hell is making it so hot? So anyhow while I was going through checking for hoses and leaks I found the vacuum hose from the egr disconnected. Of course I reconnected it. Took the car out and it just runs like trash. every time I come to a stop it idles too low and dies? The heating problem got a little better the cars running about 230 now and not overheating but with the low idle and stalling at stops its pretty much undriveable. So I am going to pull the vacuum line back off the egr? anyone ever hear of this? So 2 problems running too hot and the egr. Anyhow thanks!