That's what I can do with the old chip I yanked out of a laptop (might be a p1, don't think it's a p2 of any speed)... With the way drives are designed these days, I'd say if you have a good case, you won't gain much, if anything, by bungee jumping your hard drives. If anything, I'd think you'd risk damaging them if you moved the computer... If you think you want to make them more silent, and the noise is 100% traced back to vibration to the case, get some of the items to put between the drive and cage. You can go with something as easy as rubber washers/grommets or one of the several items made to put the hard drive into a 5.25" bay.
Personally, the only time I hear my hard drives is when the heads move to read/write from/to them... Otherwise, I don't get a peep out of them.