Oshkosh Truck Corp. said that its net income increased 26.9% to $75.6 million for its fiscal year, which ended Sept. 30, on sales of $1.93 billion. The company said its sales increased 6.5% in the fourth quarter to $508.1 million, and its operating income increased 38.7% to $43.6 million in the same time frame. Net income was up 50.8% in the fourth quarter to $26.0 million, compared to $17.2 million in the prior year quarter. President & CEO Robert G. Bohn said significant factors impacting fourth quarter results included a cumulative adjustment to increase margins on the company's long-term Medium Tactical Vehicle Replacement contract with the U.S. Marine Corps from 4.3% to 5.5%.