Hy Isaiah, I tried to cross the GM part numbers at RockAuto (3979525 and 3979527) but no luck, the Midland Ross p/ns are C4091B and C4091E, I tried to cross them as well but again no luck. You might try contacting Geoff at Alreta brake parts. The Napa number you gave does not reference the original or manufacturer part number, that makes it hard to try to cross as that number is only valid in the Napa system. You can get a 10% discount on Napa's price if you order online, at least according to their website, hope that helps.
