ok i have a 302 out of a 74 maverick bored 60 over (yeah i know its too much, i didnt build it) its got a cam and 351 heads. alumunim radiator with a shroud and big fan. so i drove her to austin from ft worth no issues, temp stays at 180. got a little hot in traffic in austin and drove back fine. Now since ive been back it has started spraying water out of the overflow tube on the radiator. I replaced the thermostat with a 160 degree and put a new 20lb radiator cap on. what could cause this? im never getting over 200 degrees on the gauge and ive checked the sending unit and its working fine. so why in the hell am i spraying water out now. i have no water in the oil either.