The 13-14 GT500 came with stainless brake hoses if I'm not mistaken. I now the calipers are different, but they still might fit. I'd PM TOB, he's the man when it comes to retro fitting. If anyone will know, he will.
When I did my Strange Brakes, I couldn't find an adapter to go from the stock hard line to the braided -3 (I think, it may have been -4???) to the Strange Caliper. I cut the stock fitting off and used a flare fitting to an AN style adapter and BAM! it worked like a charm. Not sure if that answers your question, but it's my two cents.