Ford 2003 Mustang Workshop Manual page 1102

31. Tighten the bolts in three stages in the sequence shown:
Stage 1: Tighten to 20 Nm (15 lb-ft).
Stage 2: Tighten to 40 Nm (30 lb-ft).
Stage 3: Tighten to 50 Nm (37 lb-ft).
32. CAUTION: Do not loosen all of the bolts at one time. Each bolt must be loosened
and tightened prior to working on the next bolt in the sequence.
Tighten the bolts in four stages in the sequence shown: short bolts numbered 2, 4, 6 and 8:
Stage 1: Tighten to 25 Nm (18 lb-ft).
Stage 2: Tighten an additional 180 degrees.
Long bolts numbered 1, 3, 5 and 7:
Stage 3: Tighten to 45 Nm (33 lb-ft).
Stage 4: Tighten an additional 180 degrees.
33. NOTE: Lubricate the valve tappets with clean engine oil prior to installing.
Install the valve tappets.