I m sure it s a long shot guys but I m looking for a worm gear and speedo drive gear for a 1958 GMC Napco truck with 4:57 rear and front diff ratios. Fits in the transfer case. Can also be in SM420 tranny. The speedo drive gear has 13 teeth. The one I have is barely usable. Any help or ideas would be appreciated. Other options...contacts? Thanks Craig