ISSPRO Gauges for 2004 - 2005 6.6L Duramax LLY - ISSPRO, Inc. has designed and manufactured instrumentation and sending units for a wide variety of applications for over 60 years. From concept and design to sourcing and production, ISSPRO is committed to delivering superior products that conform to the technical and operational expectations of their customers, and fulfill their own requirements for performance excellence.
