Always check the diff of a car to be scrapped in case it's a limited slip. They are rebuildable and can transfer from one diff to another (late 140/ all? 240). Having the tool to spread the case makes removing the ring gear and assembly easier but it can be done without it. If it does have the L/S and you are removing it from the case--take the pinion shaft too so you can utilize those gears if need be. I just completed installing an L/S taken from a '76 265 into an M41 equipped '73 140 (4.30 gears) rear and then put the works into my '69 144. Works like a charm.