Your VIN number: X38SKEC3976
Your Model Year is 1979.
Truck Series: Unknown, Please double check VIN number
this site is where i obtained the info
http://www.ford-trucks.com/vin-decoder/index.php
Good luck
Engine: V8 - 400cid, 4BBL carb, 167-177 HP
Assembly on: Kansas City, MO