Most U.S. ambulances are built using a Ford chassis with a 6.0-liter, International diesel engine, but supplies of it have now dried up.

A long-running dispute between Ford and its diesel engine supplier could have an unlikely victim — the nation's ambulance operators.

Navistar last week agreed to comply with a state court order and resume shipments to Ford of the powerful 6.4-liter diesel engines made by its International Truck and Engine unit. That allows Ford to continue production of its highly profitable line of F-Series Super Duty pickups.

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