Ran a search for information on these spring “clips” and found little. What is the purpose of them and should there be just a bare 1/4” through bolt or with spacer tube between. Neither of the rear spring “clips” have bolts through them however, the front spring does have 1/4” bolts through them without the spacer.
No spacer. Originally, the clamps used a special square head bolt with slightly rounded corners and a larger than normal hex nut. The reproductions that the vendors sell are modern hex headed bolts with standard size nuts.
If you have space there is no reason not to put a tube over the bolt to take up extra space. Will keep the clip tight to the spring. Springs leafs should slide not bounce apart.
Front springs almost all years used a 1/4 inch bolt. I believe that the rear spring used a 5/16 bolt.
The spring photo above looks like it could have a missing spring leaf. Mark is correct on the clamp bolts, and they used a special 1/4-20 thin jamb nut too that is 1/2" across the flats, all raven finished. This is the same nut used to hold the windshield post clamp to the front top bow on open cars.
Thanks all for the information! Going to install a 1/4-20 bolt with a 3/8” OD spacer tube 2.06” long in between the arms. Have approx. 1/8” gap between the top of the spacer tube and the spring.