Suspension and frame work, cracked LCA, advice welcome

Stick welding in this case wont be easy.6013 3/32 will likely do,welding in harder alloys and not knowing composition could cause additional cracking.
I noticed @Jim Lusk were you using flux core wire in the video?
Is there a particular reason? Just curious.

Yes, I was using flux core as that is all I had at that time. I have since added gas, but I'm still learning how to use it.