PLYMOUTH, Mich. (July 18)—Simpson Industries Inc. posted net income of $6.3 million on sales of $138.6 million for the quarter ended June 30. That compares with earnings of nearly $7 million on sales of $139.4 million during the first quarter of 1999. For the six months ended June 30, Simpson reported net sales of $283 million, a 3.9-percent increase from the first half of 1999 at $272.5 million. Net income was $12.5 million, compared with earnings of $12.7 million during the first six months of last year. Simpson believes it´s reporting strong sales and earnings for the quarter, despite more than a 20-percent drop in North American heavy-duty engine volumes, according to a written statement from Chairman and CEO Roy E. Parrott.