Reply to "Questions for the Boss Wrench"

There is a small bulb that is the warning light for your alternator, that is sometimes knocked out of its socket in the speedo. When you drive and turn, the bulb & socket swing around and momentarily ground, lighting the bulb. This is important to fix if this is the loose light, because if theis bulb is ungrounded, the next time you start the engine, the alternator field is deactivated and a perfectly good alternator won't charge your battery! Another possibility is one of the two tiny lights that illuminate your washer & wiper switches. Getting these things back in place will be a memorable experience (send the kids to bed before trying this!) They are rather high up behind the dash, near the left side. The dash is fiberglas, so start the car at night in your dark garage, in neutral, get under the dash and have someone thump the dash. The light should light up as it grounds probably against the steering or a brace.
As for your non-problem cooling system, the stock setup was for the temp sending unit to be mounted halfway up in the surge tank next to the right head. If the water level drops below the sender, your gauge wll read the air temp above the rapidly overheating water level. Coincidently, this is often about 160 degrees.... The fix is to remove the bulkhead cover from between the seats, exposing the engine. Just below the thermostat in the block is a 1/4" pipe plug; remove it. Remove the water temp sensor from the surge tank, and swap the two. Now, you'll read the water temp in the block regardless of water level in the tank. This gives a much truer picture of engine status. 351Cs run around 190-210 when things are OK; "hot" is around 245. Dealers tried to reassure people of this by recalibrating the early 0-220 temp gauges with an in-line resistor in the gauge line, which changes the true water temp reading. Later Panteras had a 0-260 gauge and (usually)no resistor lying to them.