The only thing I could find is maybe it's not Walker but ArvinMeritor's number. ARV360514 is a tailpipe that seems to cross to 45824 Walker which fits a bunch of squarebody applications. I couldn't find a direct interchange chart but when I type that number in to google it keeps taking me to Walker 45824.
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1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars (now converted to a "factory" 4 speed)