I have a 350 crate engine that is overheating at idle. I bought this car and did not build it. I have been sorting it out for about 6 weeks and I thought I had this problem fixed but I didn't. I replaced the thermostat with a new 180 degree unit last weekend and replaced the coolant. Today it was in the upper 80s and it's still overheating at idle. It has a large radiator, not aluminum, but it should be ample. There was no rust when I drained the system. It has one of those chrome Edelbrock water pumps on it and it has that convoluted flexible SS hose with about 1 1/2" i.d. on both the top and bottom. It also has a polished aluminum thermostat housing but I doubt that matters. The hose goes by the name Flexi Kool, etc. It has rubber couplings and a chrome sleeve that slip over the rubber couplings. The only two things I can think of that may not be up to snuff are the suction side hose may be too small or the water pump may be bad. I've never seen a non-leaking water pump go bad. So, I'm looking for experienced suggestions here. The engine runs at about 190 degrees when cruising (higher than the 180 degree thermostat) but will climb to 240 or higher when idling and start to boil. Not good. Thanks for your help.