[superchevy]

I'm beginning to suspect a faulty gauge, but here's what's happenning:
Installed a new, dyno-tested 454 in my '77 Silverado. New radiator, waterpump, thermostat, hoses, temp sending unit, etc, etc. Filled with coolant. Fired up engine. While adjusting carb, setting idle, and checking for leaks, noticed temp gauge creeping toward HOT. Turned on heater to see if functioning or trapped air bubble. Heater works well, slowed temp gauge rise, but still got in the red HOT, so shut her down. Upper, lower radiator hoses hot to touch. No leaks.
Let engine cool down. Drained coolant enough to remove thermostat housing.
Removed thermostat, drilled small hole in thermostat to relieve any "air pocket" issues. Refilled radiator. Fired up engine. Took a test drive down the street and back. Pulled back in driveway, watched temp gauge go back up to red HOT.
I'm going to try to verify gauge working properly.
Any other thoughts?
Thanks, SC