coolant problem

First, did you relocate the temp sender to the block? If its still in the surge tank, its pretty common to find the water level drops below the sensor level so you read air temp above the water! Second, its also very common to find that the water temp is radically wrong with a stock gauge (of which there are two different types) and sender (also two different), with & without the factory-recommended resistor (two different of these as well...). I've found that calibrating, in the car, whatever combination of gauge, sender & resistor, is a must for any sort of accuracy in a Pantera. A varable resistor makes the job fairly easy. FYI, a 192 degree thermostat, specific to the 351-C only, was stock for the Pantera. This thermostat will not fot a 351-W, and the Windsor thermostat won't work in a Cleveland.

As far as bleeding goes, get a Lisle Funnel. Seems to work 1st time every time. ( okay I only tried it twice but it worked really well both times) Try these guys, I got mine for 28 including shipping. toolcraze.com and I got it in 2 days. Their # is (818) 702-6777 and their product code is L2SRFK The cost was less than 19 but they sock on about 9.50 shipping for UPS ground.
good luck
Gary #06984

The water pump amd temp sensor are original. Up until I changed the lower hoses, the gauge always seemed to show accurately. It would regularly go up into the pucker range.