Self-studying an AP/SATest prep book that has 2008-2012 editions if I were to take exam 2016-2018?

Is it okay if I do this because I saw on the SAT College Board website as well as the AP College Board that there’s going to be some revisions made to some of the exams in the next few years. For example, and sorry about bringing up SAT subject tests, but what if I were to self-study English Literature SAT from a 2007-2008 or a 2008-2009 edition if I were to take the exam in let’s say, 2017 or 2018? Do the revisions make a big difference? What about AP World History editions from 2011-12, or SAT Bio from 2009-2010, or AP U.S. History from 2010-11? The content should be similar on the non-revised and the revised right? College Board would not take off some of the topics that have been covered on the exam in the past few years right? When it comes to test prep book editions do they really matter? Should I always buy books with editions 1-3 years before the year that has the current test format when I am taking the exam? Once again, I am self-studying, so I am not relying on classroom instructions at all. What do you guys think? Good idea?

I would be very wary about using books printed prior to the test revisions, especially for tests that have had major revisions like Bio and Chem. If money is an issue, you can always borrow from the local library or find a used copy online.

Older books that have been printed after exam revisions are fine, IMO.