This does not have anything to do with an engine change.
For some reason GM changed the threads from 13/16" on pre2007 vehicles to 22mmX1.5 on 2007's. It is not just the H2's. The 2007 Silverado Classic which is the same truck as the 2006 Silverado uses a different filter for example. The 2007 Corvette uses different filter than the 2006 Corvette and so on.
I do know that the AMSOIL EaO47 fits on the 2007's and you cannot find a better filter.
http://www.amsoil.com/StoreFront/eao.aspx?zo=1132530