84 Z28 350 Overheating form hell, got 3 fans running constant, 1 original 2 small ones on outside, air deflector is on and mounted proplery, 180 thermostat, new 3-core radiator, recently rebuilt engine, hoses are good, its off the computer, new water pump not a serpentine pump, can't figure out what the hell is wrong with it can only drive on highways not around town.
Is your cat plugged? Exhaust that is too restricted can cause more heat to build up! The engine is more suspectiable when at idle than moving. You're off the computer what is your inital timing? And a last question is when do the fan's come on and how are they controled?