I realize a custom-built bumper isn't what you're looking for, but here's a couple pics of mine in case anyone is looking to build one:
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Whatever bumper you build or buy, you need to brace it right here so it won't smash into the body. I sold the all-pro rear bumper I had on here right after the 12" bob, but it had pushed over into the body and dented both sides. The allpro would have been easy to gusset with a piece of angle iron or the like going under the body. Since mine is up higher to protect the sides better, I went through the body:
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