Bolt size..

One thing you do not want to do is put the wrong bolts in the bottom timing cover holes on the drivers side. For this reason, If you remove the power steering bracket on the drivers side do not reuse those bolts without shortening them on the cover only.

Always check the depth of those holes and make sure the bolts are shorter. You can crack the number #1 cylinder very easy, You won't even feel the bolt do the damage .
Pay attention to this... Its a very real concern...