My leakless still has a front bearing like OEM and a rear bushing with a rubber seal. I grease it with low melt point Lubriplate 130A or AA if you prefer a less viscous grease for easy application. It's resistant to water washout and has a calcium based soap. Other greases are available as water pump grease but I don't know their melting point. Lubriplate melts at 170 degrees F. Lubriplate 130-A was a replacement for RG-62A which was used as rifle grease for the M1 rifle in the WW2 era.
Ford specified a low melting point to prevent the grease from clogging the radiator tubes when it gets past the bushing. In the modern era, some leakless types have modern sealed bearings on one or both ends. Some still have a packing as a back up to seal leakage. A sealed pump normally won't allow grease past the water seal so it may not even take a half of a pump to stop grease flow. Any more pressure may blow the seal out,
If looking for pressure gun grease that can be used in early Fords, I found the information on page 58 of the 1932 Ford Service Bulletins. It specifies pressure gun grease with a lower melting point that of the normal cooling system temperature. Generally that is around 180 degrees when fully warmed up. With no thermostat, I really don't know the average temperature of the model A or B engines.