I know there are some people over on the expedition portal that have them. The biggest issue with those is cost. Also if we are talking about one for an E-series then its also gonna be a pain to find one. The only one I found for my van was the Inlad and they wanted 1k dollars for it. Id rather pay for the sound deadening/insulation/plywood instead.
2010 E150 5.4, E250 suspension, E350 springs, BFG KO2 265/75/16.
Google Sled Hockey - You won't be disappointed.