Why do you consider the Lituya Bay megatsunami to be bigger?
The prehistoric megatsunami was estimated to have a "minimum tsunami wave height of 170 m at the shoreline." The Lituya Bay crest was estimated at 90 m.
The run-up at Lituya Bay might be higher but, to quote from this Science paper, "run-up is a complex process governed by local bathymetry and topography".