boxing LCA should I go all the way around or just bottom

I'm looking for some advice on which will be strong enough. I was going to re-enforce the exsisting metal so its as strong as an aftermarket unit. I'm not sure how much flex those stockers have, so would a 1/8 inch thick plate underneath the LCA be enough to give it strength, the stock unit is 1/16 thick. I could go all the way around the whole thing boxing in the exsisting metal, but I feel this would be overkill.
I could also just make a complete whole boxed unit and drill some holes for the new aftermarket bushing, but once again this might be more work than what is needed, when I could just strengthen the old one up.
Also from what it looks like the bushing are not pressed in, Is this correct?

I just put a 1 1/4" by 1/8" plate on the bottom of mine and poly bushings.