Any one use a roll cage for their Revo?

[Hickoryhead]

I have seen roll cages on Ebay. The one I am talking about goes under the body. I bought a Gorillamaxx G2R chassis. The guy who sold it to me included the used body he had. It has splits going from the hood of the body to the sides. I can tell the Lexon ripper due to crashes where the cab of the Revo was smashed into the tranny of the truck creating the splits. I think I will buy one of those inner roll cages if they will work? I don't like the looks of the exterior roll cages. Any thoughts or experiance? Also I am not sure what size to buy. I see they are built for the 3.3 or the 2.5. Which size is equal with the G2R chassis? Thanks.