Ford 2003 Mustang Workshop Manual page 1583

102. Install the rear oil seal retainer plate and tighten the bolts in the sequence shown.
Tighten bolts No. 1-6 to 10 Nm (89 lb-in).
Tighten bolts No. 7 and 8 to 20 Nm (15 lb-ft)
Tighten bolts No. 7 and 8 an additional 60 degrees.
103. Using the special tools, install the crankshaft rear main seal.
104. Using the special tool, install the crankshaft oil slinger.