Reply to "Checking the water temperature"

FYI, I run a plugged bypass hole as do many Pantera owners (since 1989 on this engine). Some aftermarket aluminum waterpumps such as the popular Weiand unit have no bypass passage, which does the same thing. I run a 190 thermostat, and had 190-200 degree water all the way to 'Vegas last year (550 miles one way). While at 'Vegas, I added a 160 theermostat as an experiment. Drove home with 190-200 degrees showing on the calibrated gauge. Conclusion: thermostats don't raise nor lower the 351C engine temperature on long runs. But with a plugged bypass, you can use about any V-8 thermostat you can find. Mine is currently for a 289 Mustang which is easier to find on the road than the special 351-C unit.