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I can't say I'd get one over the other at this point as I have just replaced the Napa 535 belt with the Goodyear 537 belt. The Goodyear 537 is a tight initial fit at 53 3/4" vs the Napa's 54 1/8" but it fits none the less. The Goodyear is definately louder than the Napa if that is anything you care about.