Thanks for the help. Also do you know any good resources for Section 1 and 2?
MCAT stuff available online is particularly good IMO for section I. I reckon
Examkrackers - 101 Passages in MCAT Verbal Reasoning is a decent resource to practice SI-type questions. Poetry analysis books are good too - where you can see how different types of prose are discussed. Reading novels with unusual writing styles is a good idea too - for example Cormac McCarthy's books, which have a engaging, complex prose (and they're a good read too! Check out
The Road to start with).
I found some value in analysing complex diagrams/charts that illustrate a humanities concept or phenomena; a good source for these being humanities journal articles - particularly social anthropology (which seems to be a common topic in SI stimulus materials), economics and political science publications.
An example of exactly the type of diagram that turns up in the GAMSAT is this chart below which portrays a social system of what living and migration arrangements a particular culture makes before and after they marry (source:
http://etudesafricaines.revues.org/135):

A number of questions were asked about a similar diagram in SI of the 2011 GAMSAT - specifically about avunculocal and matrilineal societies IIRC. Practicing comprehension of the relationships and information in such diagrams was quite useful in my case.