Fast Transit: Earth to the Moon

Pretend a hypothetical SSTO tops off its tanks in low Earth orbit. It
now has plenty of fuel to get from LEO to the lunar surface. In fact,
it has 4000m/s of excess delta-V on top of the fuel needed to get from
Earth orbit to land on the moon.

About how much time can be shaved off the flight if that extra fuel is
used to hasten to the flight between LEO and lunar orbit injection?

(Obviously, the extra fuel needs to be split between acceleration and
braking.)

Mike Miller, Materials Engineer