Just make sure you know what cylinder is TDC, and mark lots of stuff (cam, lower pulley, etc) in case something gets bumped & rotates. Most instructions say to go to #1 TDC, because most manuals have instructions on how to get everything lined up again off #1 TDC (in case something gets drastically out of wack). Some people suggest to use lock-tite when re-installing crank pulley to help avoid the dreaded keyway damage.