Re:Leaf spring shackle

Yes it is.
The bolts have a press fit spline to one of the shackle plates.
When the bushings get really worn out, the bolts can come loose eventually.

Sorry for not seeing this post before

On the same note, since i have had some experience with the aftermarket shackles, beware that the longer ones will make your springs sag faster from bending further than they can cope with. And some of them do not go so good together with the shackles stops making the springs bend further and even faster sagging.
i have also bad experience with the poly bushings that when driven thru dirt and sand wear out very fast. and on this car the softer rubber works better anyways in my opinion.

But for your project Martin original will do of course

I dismantled the springs on my SJ, linished the contact points and re-assembled them with copious amounts of a waterproof grease. I then wrapped the springs with lengths of inner tube, 2" wide cut from lorry inner tubes. The rubber is held together with electrical tape, just wrapped around the whole lot. The effect of smoother running and improved articulation is very noticeable and, in my opinion, well worth the effort. High end pre war cars used to supply leather gaiters to do the same thing.

Roger

On my SJ the springs have worn a ridge inbetween them that made this nice grinding noise and at full turn also a large knock when they slipped over. The noise fit right in with all the other rattles making a concert almost, but this knock was a bit too loud so light greased now to tone it down.
I am actually not kidding now.

Apparently the OME springs are built with graphite pads to help them slide. We’ll see!

From memory, I fitted Rancho plus 50mm springs and they had nylon pads but green lane runs and RTV trials would quickly pack the leaves with mud and you were back to square one. My idea to wrap the springs worked well and would last 12-18 months before the need to do it again but that included a lot of mud work.

Roger