Why did my new idler arm come with such looong bolts?

[chillware]

I don't understand why all new idler arm kits for the 64-66 trucks come with such looong bolts. What do they expect me to be bolting this to??

The new bolts are so long that they come out past the other side of the frame rail, and there is only maybe an inch of thread on them.. the original bolts are only about 2 inches total in length..

Attached is the pic from the LMC catalog, i should take an actual pic of these bolts tho.. i just don't understand.. ??

any thoughts?