About

About Interstate Assembly Systems About Interstate Assembly Systems We’re upfitting experts. From custom design and build to work ready spec trucks, we set the industry standard for reliability and service for the life cycle of the truck. Our engineering team is ready to work directly with you on concepts, designs and product development, ensuring that you can serve your customer proudly. We’re the cost-efficient, single-source builder to meet all of your heavy truck upfitting needs. We're upfitting experts. From custom design and build to work ready spec trucks, we set the industry standard for reliability and service for the life cycle of the truck. Our engineering team is ready to work directly with you on concepts, designs and product development, ensuring that you can serve your customer proudly. We're the single-source builder to meet all of your heavy truck upfitting needs, including Spec builds, customs builds and refurbishment. We’re upfitting experts. From custom design and build to work ready spec trucks, we set the industry standard for reliability and service for the life cycle of the truck. Our engineering team is ready to work directly with you on concepts, designs and product development, ensuring that you can serve your customer proudly. We’re the cost-efficient, single-source builder to meet all of your heavy truck upfitting needs.