Place roast in an aluminum foil-lined roasting pan. Cut 4 to 5 (1-inch-deep) slits across top of roast. Sprinkle evenly with salt.
Stir together garlic and next 4 ingredients. Pour mixture evenly over roast, rubbing mixture into slits. Cover and chill 8 hours.
Bake, uncovered, at 325° for 4 1/2 hours or until meat thermometer inserted into thickest portion registers 175°. Remove from oven, and let stand until thermometer reaches 185°.