Although I can't rule anything out, I can't think of any reason why anyone would intensionally set it up this way, unless it came from the factory like this (even then seems odd). The trans is original and that's the end with the 2-1/8". Specification calls for a 7290 shaft for my car. I suppose someone could have replaced the 2-5/8 slip yoke with a smaller one and then had the driveshaft end replaced with a smaller yoke to match but I don't know why anyone would go through all this trouble. I can't think of any other plausable reason for this. From what I understand, this should be the same driveshaft used on 440 & 426 Cudas. Anyone else with an AAR know what they have?