Beginning of the End - my 73, 340 Duster rest-o-rod???

The rear was probably an 8.75, but without the build sheet, it is hard to say what gear ratio and if it was a sure-grip. Or the rear could have been an 8.25. I think the cutoff for A-body 8.75's was sometime around the end of '72 and the beginning of '73. That's no 4 speed car though. D13 means 3 speed stick.