CUMMINS ENGINE <CUM> SEES IMPROVED EARNINGS Cummins Engine Co said it told shareholders higher engine orders to the North American heavy-duty truck market will result in improved earnings in the first quarter. Cummins said the company should make progress this year and next toward its goal of five pct profitability. Cummins recorded net income of 3,743,000 dlrs, or 38 cts per share, on sales of 516.9 mln dlrs. It said it expects 1987 North American heavy-duty truck production to total 135,000 units, an 8.5 pct increase from 1986. Cummins said it expects capital expenditures to total about 155 mln dlrs, down from 274 mln dlrs the year before.