Reverse will crunch no matter what,
It dosnt have. Synchro
So you have to be practixly dead stopped to change into it without crunching also don't try and get into reverse like your changing gears at a racetrack, nice and easy into reverse
I've had three jap cars and all had that problem
Found out they didn't put synchros in the reverse gear.
Don't bother getting one synchro, it will be like 3-500$ just for the synchro
If you get it fixed
Have it fully rebuilt with strengthend synchros and bearings
If your going to bother, if not try amsoil good **** that stuff
Or caltex easy shift
Good luck