Ford 2003 Mustang Workshop Manual page 1446

4. CAUTION: The camshaft timing marks must be correctly lined up or damage to the
valves and pistons can occur.
NOTE: The copper links on the timing chain may not line up with the timing marks on the
sprockets.
Make sure the timing marks on the camshaft sprockets are correctly positioned. If necessary,
turn the crankshaft one full turn clockwise to correctly position the sprockets.
5. NOTE: LH shown; RH similar.
Remove the two bolts, the timing chain tensioner (6L266) and tensioner arm (6L253).
6. CAUTION: Unless otherwise instructed, at no time when the timing chains are
removed and the cylinder heads are installed is the crankshaft or the camshaft to be
rotated. Severe piston and valve damage will occur.
Remove the LH and RH timing chains and the crankshaft sprocket (6306).
Remove the special tool from the crankshaft.
Remove the RH timing chain from camshaft sprocket.
Remove the RH timing chain from the crankshaft sprocket.
Remove the LH timing chain from the camshaft sprocket.
Remove the LH timing chain and crankshaft sprocket.