Hello, I need to replace my internal HDD on my late 2011 MBP, 13 inch. The drive I would like to purchase does not appear to have a normal enclosure like the one that came with my macbook. Is this going to be a problem to install "as-is" in my macbook? I know that normally internal drives come with top casing that hides the internal components. I don't understand if this is simply to conform to the 7mm height standard or if I will need to purchase an additional enclosure to be able to install this drive in my macbook. Seagate Momentus Thin 320 GB (7mm) The HDD I can acquire and want to install Seagate Momentus 320 GB (9.5mm) The similar but slightly taller HDD model with the "normal" casing.