[Marshall V. Daut]

Did you re-install the engine splash pans? Besides functioning as part of the electrical and cooling systems, they can be helpful in tracing a coolant leak.
For example, if you can see fresh water stains or coolant tracks running down one (usually the driver's side), that will narrow down where to look. As suggested, it might be a faulty petcock, although to find as much water on the pavement the next morning as you describe, the petcock would really have to be bad. Water dripping from the water pump (cracked housing, bad gasket, faulty packing nut, worn packing, scored shaft) usually drips down the driver's side of the engine, running behind the generator and then along the engine block's rail before it drips onto the engine splash pan. You undoubtedly installed new hoses, which tend to incrementally compress like a head gasket, requiring re-tightening after a few heat and cool cycles until the rubber won't compress any further. Otherwise, coolant will seep past the hoses until the clamps are tightened again and again. The water return gooseneck's gasket on the side of the engine could be leaking or from between the cylinder head and engine block.
All of the pervious suggestions are on the left side of the engine. Coolant leaks don't usually happen on the right side of the engine, unless a head gasket blows out there or the block develops a crack in the water jacket. Since you have a new high quality engine block, we can rule out a cracked block.
Up top, check that water isn't leaking past a cylinder head stud. #8 stud that anchors the distributor cable is a prime source for leakage if the stud's threads hadn't been coated with sealant before screwing it into the block. #7 stud behind the upper gooseneck can also be a leaker, as I discovered on a engine when I left the nut off for the evening. A puddle beneath the car the next morning showed me that coolant had leaked past the "naked" #7 stud. Check that the upper gooseneck gasket is functional and that there is no crack in cast iron neck itself. I assume that you are vigilant about re-torquing the cylinder head nuts, following the proper sequence and torque values? Failure to do that will result in a blown head gasket or seepage between the head and block.
Feel inside the front crossmember trough for wetness. That will tell you if the lower hose is leaking or if there is a leak in the radiator. Feel underneath the crossmember where the front engine mount stud exits. Wetness there also points to a lower hose or radiator leak, that being the lowest place, which water always finds. Check the firewall for signs of splattering and water drops. That usually means a radiator or water pump leak that blows coolant backwards onto the firewall.
There are only so many places for the coolant to leak. Keep looking and eliminating suspects until you find the source.
Marshall