Idler arm spacer?

When redoing the front end of my 69 I noticed a homemade spacer between the idler arm and the frame rail about 1/4 inch. I removed it when reassembling everything because it didn't belong. On another forum I found at least 5 other cars with the same mod. That make me think it is some kind of old school mod to improve the geometry like the Shelby drop or the quick steer kits from the 65-66"s. Does anyone know anything about this?? Thanks

thanks for the reply. That make sense but since it works with or without the spacer, do you know what kind of difference it's supposed to make in steering response?