Here is a link to a thread in Madden about what the sliders actually do to adjust gameplay. It is very good and I highly suggest reading it and considering how they may work similarly in NCAA.
http://www.operationsports.com/forum...ally-work.html
For instance - He surmises pass blocking affects how likely the pass block animation (suction block) is likely to be triggered, while pass rush affects the likelihood that once a block has been initiated, the defense player will be able to shed that block.
So, if you like to blitz, and are tired of seeing 7 rushers all getting picked up by blockers, you would lower pass block, but not necessarily raise pass rush. Raising pass rush would make a standard 4 man rush more effective as they are able to more easily shed the blocks. Lowering pass block means it is less likely that a blitzer will be sucked into a block.
Credit to Bill2541