Big Book 4th edition — the core 164 pages

"As in previous editions, the basic text remains the same. It is the balance of the content (personal stories of AA members) that has changed"

"The 1995 General Service Conference recommended that, 'The first 164 pages of the Big Book, Alcoholics Anonymous, the Preface, the Forewords, the Doctor's Opinion, Dr. Bob's Nightmare and the Appendices remain as is.'"

"as always, the first 164 pages remain unchanged.
The first 164 pages of the Big Book, Alcoholics Anonymous, the Preface, the Forewords, the Doctor’s Opinion, Dr. Bob’s Nightmare, and the Appendices remain as is.” (Underlining a strong consensus throughout the Fellowship, this action was affirmed by the 1997, 1998, 1999, and 2000 Conferences.) "

Big Book 4th edition — rest of the book

"The new edition ... contains the experience of 42 sober alcoholics — 24 new and 16 'keepers' from the third edition"

Big Book Stories: Third Edition versus Fourth Edition [oahow.squarespace.com]

[silkworth.net]

Big Book 1st edition

[silkworth.net]