A small word of advice. If your computer will be under your control the whole time, be sure to lay it on its side during transport so the motherboard is sitting horizontally and facing up with the CPU on top.
If you must transport the computer in the tower position, or if the computer will not be under your control during transport, then I recommend you remove the heatsink fan assembly. This is especially important if you have a large aftermarket cooler. If the computer encounters rough handling and bumpy roads, with the tower in the normal upright position, the heavy heatsink can put undue stress on the CPU socket and actually create micro-fractures in the motherboard, and in some cases, break the socket and come lose, then bang around inside the case for the rest of the trip. Not good.
In fact, just to be safe, I would remove the HSF assembly anyway.