The last few times I fired up my dirty old girl, the dashboard temperature gauge was reaching uncomfortable heights, which could indicate that the left bank is overheating. (These old things have seperate cooling circuits for each side of the block, as they were basically two 4-cylinder blocks cast onto a single crankshaft.) Drained some of the coolant out of the flathead so that I could pull and test the thermostat on that side which has the sender to the temperature gauge in the dashboard. That head only has one boss drilled and tapped, the other has two. I have previously installed a Mooneyes temperature gauge directly into the head on the other side.
I placed the 180°F thermostat in a pot of hot water on the gas hob and it opened before the water boiled (212°F), so it isn't faulty. Then I removed the sender from that head and replaced it with the second of the Mooneyes temperature gauges I bought. That will let me know if that bank is actaully overheating or not, next time I fire it up.
Then I made a short extension for the sender lead and screwed the sender in the head on the other side, removing the switch for the electric radiator fan. I have previously wired that 2-speed fan to run on a pair of manual switches as it wasn't kicking on at all.
While I was doing that and had the right side upper coolant pipe and hose off I took apart the linkage for the four-barrel Holley and rebent the lower section (which had been done a bit rough-and-readily) so it had better clearance from the rubber hose and could use the other hole for the ball mount for the pedal rod.
I'm not too impressed by the state of the rubber hoses where the thermostats have been cutting into them for the last twenty years. I'll see if I can find something to replace them with when I'm out tomorrow before putting the coolant back in and discovering whether the temperatur sender is off or the digital gauge needs recalibrating.