When the 106th Congress convenes in a couple of weeks its top legislative priority should be an across-the-board 10% income-tax cut for businesses and individuals, says the Washington-based National Assn. of Manufacturers (NAM). The tax reduction is necessary to keep the U.S. economy growing and would "also take the burden off continued interest rate reductions as the only vehicle for stimulating growth," says NAM President Jerry J. Jasinowski. A 10% cut would add an extra 2.1% to U.S. gross domestic product by 2002, the business federation estimates.