I suggest if the stays and shrouds are still in good condition, shorten the mast to match the old one ( 26'-3") A higher mast only adds weight to the boat, on the other hand, correct shroud / stay tension is a MAJOR factor in the boats perforance.Once you've shortened the mast and installed it, measure 30" up from the deck and put your lower BAND around the mast with the TOP of the band at the 30" location.Then suggest you lower the mast and measure 23'-0" up from the top of the lower band to get the location of the BOTTOM of the upper band and install your upper band around the mast.Now you have the correct distance for your main sail hoists.Good luck.
T Sharplin, measurer/fleet captain - Fleet 38, Vancouver, B.C.