the spec pressure is 75inch lbs of hold down force, so unless you really have some skill, stick with factory holdowns. Quick note, if you go for a mod block, the zaleman 7000 block the 1st 2 dimm sockes on the msi board, and I did have great success with the Aerocool HT 101, with 2 80mm fans push pull. Looks cool too, but don't recomentd for lan party rig, to heavy.