Hi, I've purchased a 2012 (2010) 3.2Ghz mac pro and got a great deal, I'm looking at buying a 2009 dual quad processor board only. Do I need 'lidless' versions of the W3690 or similar to enable the heatsinks to sit properly, if I do on a 2009 board do I need them on a 2010 board? Am I right in saying it's a firmware upgrade on the 2009 dual board to bring it up to 2010 firmware? I then want to install 2x W3690 to the 2009 dual board. My questions are, is it compatible electrically and in firmware with my 2012 (2010) Back pane logic board? Can the cooling in my stock quad core handle the thermals of two 3.46Ghz Hexcores? The heatsinks required for dual processor 2009+ boards, are they all the same?(different part numbers per 2009, 2010 and 2012)? I need to buy two heatsinks as I currently have a single heatsink for my quad core. Heatsink A and B as they're commonly called have a large price difference. Is heatsink B actually any different? i.e can I use 2x 'heatsink A'? Thanks for your time.