We are trying to repair/replace the rear in a 64 1/2 ton with a 12 bolt rear and a series 4 carrier (crown?) The pinion gears have eaten into the housing. We would like tosimply replace the carrier but, we seem to have 17 spline axles which were only used for a couple of model years. The info we have indicates we need 30 spline axles in order to buy a replacement carrier of most any type. The big question is - where do we look for 30 spline axles in other later model trucks so that we can use the old axle housing. If that cannot be reasonable accomplished, does anyone know in which vehicles would we need to look to find a complete axle of the correct width. So far, I have not been able to find a list of GM axle widths to help in tracking down a donor vehicle. Any help along these lines would be greatly appreciated.