is this a 55.1 or 55.2? GM never left off the identifying trim on a truck, although it's conceiveable it could be a service replacement, which wouldn't have any trim, and if it fit more than one year [55.2-56] they'd leave off the holes .... but if it's an exact match for your original, then ya don't really need any "help", even for the hole locations, do ya
Bill
