"4.6L engines may have 6 or 8 bolts to attach to the crankshaft. Romeo built engines have 6 bolts and Windsor built engines have 8 bolts. All Cobra engines have 8 bolts. The 8th character in the VIN is (X) for Windsor engine plant or (W) for Romeo engine plant."
If you have 11 bolts on your valve covers its a 6 bolt crank. 14 bolt valve covers you have 8 bolt crank Windsor motor. Long as you haven't swaped heads or motor