Thanks Buz! I saw your post above and called a local welder who told me that welding cast aluminum won’t hold after a while and that I’m better off replacing the brackets. He didn’t sound like he wanted to deal with welding aluminum....oh well. The full driver side assembly arrived at my dealer and Im picking that up today and installing it tomorrow.
In the long run you're better off with OEM (unwelded brackets) but for anyone else who may have this issue, my welder was also concerned initially about welding them, but after he was finished he mentioned that he couldn't believe the quality of the metal used. He initially thought is was "cheap Chinese pot metal" that would not weld well, but after he was finished he changed his mind and said he couldn't believe how well it took the weld.
I figure FCA uses a decent metal for those brackets since you could have two 250lb guys standing on that board simultaneously.
I'm not worried about the weld since 99.9999% of the time it's only holding up a 5lb running board. Besides I'm pretty sure if it breaks again it will be anywhere but on the weld. Kind of like when a broken bone heals.