Nissan Repair: frozen connector, nissan urvan, high temp paint

Question
I am having difficulty removing a badly corroded hose connection from the underside of the intake manifold on my Nissan urvan motor. The motor is a Z motor(1985 nissan Urvan automatic). I have managed  to modify a socket to fit around the hose connectors, all three of them, but cannot budge the fitting even with a two foot pipe on the wrench. Any suggestions please. Also if you can tell me what is the purpose of the coolant being chanelled to the intake manifold is it to do with the heater or is it for temp. control of the manifold. I thank you in advance for your help.
Stan


Answer
upon research i have not been able to find out why you have coolant lines coming to your manifold.  if they are leaking due to corrosion and absolutly need to come off, my suggestion would be to have the new lines ready to put in (buy before you take off) and keep trying to take them off with force (using longer pipe) also try penetrating spray or some sort of debris loosener.   if they arent leaking and just "annoying looking" try to sand off the corrosion and use a high temp paint to make them "look new".