I don't understand why everyone goes to Chevy Duty, my experience is that they don't care and the catalog is no help for determining correct year for the parts. This is especially true for 55.1 truck owners. They don't reply to email and the people who answer the phone know nothing useful. Jim Carter's business at oldchevytrucks.com has by far the best catalog and he is a patient, honest and extremely knowledgeable man.
