Yes. The bolt and nut holds the ball securely from moving. The dubro plastic eyelet moves nicely on the ball. It has a lot loss play than the stock ball cups. For this reason, I suggest buying extra dubro swivel ball links. Most are perfect, but some come from the factory and the movement is too tight. I tried heating up the ball, and it works perfectly until the heat goes away, then they go back to being too snug. So I found it's easiest just to buy extra and pick out the 4 best ones.
NOTE: The holes in the CRC Delrin steering blocks
are a little too big for the Dubro swivel link with the 256 bolt
Although the 4-40 bolt from the all 4-40/4-40 version
would probably fit the hole better, I thought that it was a tad overkill and also heavier, so I bought the 256/4-40 version. Since the bolt and screw can be tightened down nicely, the small 256 bolt doesn't matter much as long as you don't hit anything. If you hit something, there is a chance that it may change position slightly and cause a toe-in or toe-out. So, I made my own custom spacer to make the 256 bolt fit perfectly in the steering block holes. Here is a tutorial on how to do it:
1. Buy some 1/8" brass tubing
2. Use a thin dremmel cut-off disc to make a cut lengthwise down the tube (about an inch or less is all you'll need.)
3. Then cut off some pieces that you'll need for the spacers. These are now in the shape of a "C".
4. With a needle nose, bend the "C" into an "O" around the 256 bolt.
5. Place the 256 bolt into the dremmel.
6. Spin the dremmel up, and use some sandpaper to spin the brass spacer to reduce the wall thickness of the brass spacer until it fits perfectly in the steering block hole.
Making the custom brass spacer is a lot of work, but I'm a perfectionist. I like it done right. No slop. The servo saver does not need anything special. The 256 bolt fits inside a stock servo saver perfectly.