That is a 60 series 5 speed. A pic of the lower rear half will tell if it's a 60A or 60L and these only fit on A series. I would reccommend fitting the throwout bearing off the old gearbox on to avoid any issues there on fit up. As for the crunch, the synchro rings are still available but I would also reccommend replacing the energising srings and lugs. They can often cause problems shifting. I had one recently that had thrown a energising spring and did not need a synchro at all.