Tremec 3650 6 or 8 bolt flywheel

1980-95 5.0L 50oz. Imbalance, 157 tooth 563100-50 $410/ea Qty:
1996-98 & 2001-02 4.6L GT 6-Bolt, Neutral Balance, 164 tooth 563405 $365/ea Qty:
1999-00 4.6L & 1996-02 4.6L Cobra 8-Bolt, Neutral Balance, 164 tooth 563407 $365/ea Qty:
Some 5.0L stroker applications 28oz. Imbalance, 157 tooth 563100-28 $410/ea



From their website.
 
according to the ford racing catalog...Romeo built engines have 6 bolts and Windsor built engines have 8 bolts. The 8th character in the VIN is (X) for Windsor engine plant, and (W) for Romeo engine plant. My 02 GT has X as the 8th char. in the VIN-as did my 98 aswell.