Chrysler is halting output at its Mack Engine Plant II in Detroit, where the auto maker currently builds the outgoing 3.7L V-6 engine.

As part of its goal to reduce overlap, Chrysler instead want to focus on manufacturing its 3.6L Pentastar V-6, a 2012 Ward’s 10 Best Engines winner. The Pentastar V-6 is in line to replace six of the auto maker’s V-6 engines through 2014.

Chrysler is looking to reassign the more than 200 workers affected by Mack II shutdown. In a notice filed July 9 with the State of Michigan’s labor office, the auto maker says the layoffs “must be considered permanent.”

The plant, which opened in 2000, is expected to idle in September, Chrysler says.