I recently experienced clutch failure on my Dart. At first I thought it was hydraulic, but it turned out to be the failure of the cross pin that secures the forked carrier that carries the carbon thrust bearing in the bell housing.
Once I had dismantled the offending item, I reamed out the hole in the cross shaft to eliminate any wear and machined an oversize taper pin to fit the newly sized hole, utilizing a 7/16 unf capscrew.
The car is sixty years old so, hopefully it should be good for a few more years.
I am relating this as I think it is an item that may well be overlooked when cars are being restored and it unfortunately means removal of the gearbox to rectify.
In case it happens on my other Dart I have made a spare pin, as I have had the other car for nearly 20yrs. and it could go at any time.
Hope this does not happen to anyone else soon.

Dave.