07 is 6061 aluminum, there were ~65g and ~62g versions, along with small bearing, highwall and one run of small bearing highwall
08 is 7075 aluminum, unsure if there were any small bearing. no highwall version im aware of
09 had the “classic” version which was identical in specs to the standard 07 version and then the regular 09 which featured a highwall. regular model was 7075, idk about the classic version
2010 was 888x which had the highwall standard. i believe 6061
2011 was the 888.11 which did not feature a highwall. again i believe 6061