Suspension Bolts?

[fords4life91]

I am FINALLY getting around to installing my new shackles and shackle mounts this weekend!! My question is, I was planning on use grade 8 bolts for everything, BUT will these work for the bolts that go through the leaf spring and hold the leafs to the shackle or am I gonna have to use a hardened type bolt???

 

[Skandocious]

Grade 8 is tough stuff, I imagine it would suffice. That's what I used for my class IV hitch and the instructions only called for grade 5.