Place ham, fat side up, on rack in roasting pan. Insert meat thermometer into thickest part of ham away from fat or bone.
Roast ham in oven about 3 hours.
With 20 minutes before the 3 hours is up, prepare Glaze (Makes about 2 cups): Combine brown sugar, vinegar, raisins and peach syrup in medium saucepan. Bring to a boil over high heat; reduce to low and simmer 8 to 10 minutes.
In small bowl, dissolve cornstarch in orange juice; add to brown sugar mixture. Add remaining ingredients; mix well.
Cook over medium heat, stirring constantly, until mixture boils and thickens. Remove from heat.
Remove ham from oven. Generously brush half of glaze over ham; return to oven 30 minutes longer or until meat thermometer registers 150°F.
Remove ham from oven and brush with remaining glaze.