Ok, I am dismantling my dad's 2003 Mustang GT to get down the the head gaskets(which I'm pretty sure he has blown). I am following guides from alldata.com and Haynes repair manual and they are both telling me I need to hold the camshaft still with a special tool called a camshaft position aligner. However, when I look it up online I cannot find that tool anywhere? Now I have rebuilt engines before and never had that to use this method but with both guides saying to use it or cause damage, I want to be sure I don't screw it up. I mean obviously I understand that getting the timing right is important but is it crucial to hold the camshaft still.