Google used to index only the first 101 KB of any web document (that's why you may have often seen 101k as a document's size on Google SERPs). It seems that it's no longer the case: a search for The Project Gutenberg eBook of Ethics gives as first result the page http://www.gofigger.org/hphist/gutenberg/7ethc10.htm which is 513k.

We reported previously that Google might be indexing more than 101k but at this time we couldn't find any example.

Via WebMasterWorld (Google cache page size limit change) and Google Fan (Google cache rising above 101K)