Chrysler plans to invest more than $280 million on equipment and technology improvements for the Jefferson North Assembly Plant in preparation for production of the next-generation Jeep Grand Cherokee and two unspecified new models. The investment would cover tooling and machine improvements, a new conveyor system, chassis assembly and line upgrades and an improved paint shop. The upgrade process would begin in July and be completed in 2010. It is expected to generate 419 new Detroit-area jobs.