It would definitely help. High-RPM drives run very, very hot, and if you have a fan blowing on them, or better yet in a cooling unit, then all the better.
It's also possible that certain drives can handle better than others' your Raptor may have been less able to cope than another.
If you can spare a cooling unit (http://xoxide.com/vavohadrcosy.html)
or jury-rig a fan to blow on them (a PCI rack, http://xoxide.com/sunbeam-wherever-pci-rack.html),
then all the better. They run best with cooling. They may be able to handle it, but th their lifespan will be longer if you cool them.