My 1941 1/2 Ton pickup need the old 221 rebuilt, so we took it apart....bored it to 239, replaced the cam with a geared '48-'53 cam so we could run an MSD Electronic ignition, swapped out the crank pulley for a double sheave pulley, of yeah, converted to 12 volts, so put an extended pulley on the altenator up top. All this went along just fine, then came the water pump issue. I technically need a pair of '37-'48 'Bg Truck' water pumps with the double sheave pulleys so the fan belt would be properly aligned, but those are rare and expensive when you DO find them. So, I took a pair of '48-'53 regular truck pumps which have the extended pulley shaft.....they work PERFECTLY.....until....and this is the my MISTAKE part, I filled it with water and antifreeze..........fluid CASCADING down the front of my nice new engine......

In 1949, ford added a water passage opening in the TOP of the water pumps....I did not KNOW that.....I recovered though......1/2" freeze plug added to each water pump and we're good to go

 

steve, thank god it was external and not in the engine! thanks for the tip.