I have an 8 3/4" rear end and axle housing with leaf springs that I removed from a '73 Charger SE with 400/727 drivetrain. I am currently having the rear-end components rebulit/upgraded, but I am having trouble with identifying the leaf springs. The leaf springs each have 5 leafs, and the bottom leaf on each has the part number 3643752. The rear end was a 742 case (3.23 posi) and the setup did have the rubber isolators from the 73-up cars. I have no reason to doubt that these leaf springs were original to the car, but I guess it is possible that a previous owner could have changed them. I have checked the interchange manual, parts manuals (1972,1973 and 1974) and the part number search tool on MyMopar.com with no success. I would just like to know what exactly I have so I can go about ordering the proper bushings, and/or upgrading if I find that they aren't what I am looking for. Thanks for any assistance!