I recently put in a new 350 w/ a holley avenger carb in my camaro. I also installed a set of relatively cheap autogage gauges to monitor my oil pressure and water temperature. The water temperature gauge gets up to around 260 within 5 minutes of driving. I checked the rad. cap, put in a new 160* thermostat (and checked to see that it was functioning), and replaced the temp. sending unit. The gauge still reads over 280 after 5 minutes of driving. What could cause this? Could it be the gauge itself? I am leaking coolant from the back of the engine compartment, but I dont know where exactly. When i accelerate hard a lot of coolant drips onto my Y-pipe. I cant tell if it came from the hoses going into the firewall or my heater core. Could that cause the temperature to get that high that fast? Could it be my old water pump? How can I check to make sure my water pump is functioning correctly? Thank you for your help.
Matt

 

There's a guy at fl-thirdegn.org, that is having overheat problems, you might check there.