So here we go...
As can be seen, though the bushes themselves are the same diameter and work on the same size ball stud, the retaining clip comes in at a different point... that's the groove around the outside of the bush. There are also channels for grease.
Now that I have it apart I can see that there's no real problem with the originals so I guess they'll get put back in.
The original rods that pull on the Z-bar work through a bell-crank under the floor. So there's a vertical rod which appears to me to be about 5/16 thick, it has little 'horizontal' pieces welded to it and they go into the clutch actuating lever up at the pedals and the bell-crank at the bottom. It all looks fairly flimsy to me, though obviously mine did lots of miles in the slant 6 van from which it came.
However, it is a wear point at each end, the horizontal pieces must wear and the holes in the points where they run must wear over time.
The rod from the bell-crank to the Z-bar is similar, though maybe it has bigger pieces going through the bell-crank and the Z-bar lever to which it links. I can see plenty of wear in that hole!
So I'm going to use 8mm female rod ends. These are not very expensive at all...
...about $AU8.00 for two including postage. Of course I need four. The ⅜" female rod end shown on the replacement clutch push rod was dearer, about $AU17. The 8mm rod was only $AU4.50 and some nuts and bolts pushed another $AU15 onto the price list.
To make the clutch push rod I got two 4" ⅜" UNF bolts with thread all the way to the heads. I've chamfered the heads and welded them back to back, then cut the short end to the required size. A bit of judicious grinding to emulate the original flat on the thread and it was just a matter of grinding back the weld to form a 9/16" hex and bolting it all together.
Thus far the 8mm rod ends haven't arrived, but they should be here early next week. I should be able to fit it all up about this time next week when I once again go to the shed where the van is stored for the moment.
I've made the threads on the rods a bit longer than should be needed as I don't know how far the rod ends will screw on nor do I know the exact length of the vertical rod. I can cut it if needed, but I can't do any more thread once I get to the shed. I can also use long (about 1" long) locknuts if the exposed thread is too great.
With all of this I hope to make it more durable and smooth-running and take away some of the fears I have of those original flimsy rods breaking when I'm a long way from home.