Tariff change for aluminium ingot: duty converted from ad valorem to specific rate and notification limited in duration. The notification amends the customs duty on aluminium ingot by substituting the previous 35% ad valorem duty with a specific duty of Rs. 3,700 per tonne and inserts a provision limiting the notification's force to the period ending 30th September, 1987, pursuant to the Central Government's powers under the Customs Act.