Good advice. Got the caps off, dropped the whole business out and tapped off the ring gear, which was the goal. Pulling this open diff from a donor 65 Newport. Plan on a new sure grip from Doc Diff. Trying to re-use ring gear and pinion. Cost savings plus i like the 3.23 ratio. Had never messed with a diff before so was following disassembly instructions and got stuck at that screw.