I tried searching, but came up with nothing. I want to build an enclosed four place gooseneck snowmobile trailer, because of the need for a v nose front end, I've been thinking about a single tongue coming out from the V nose. It would look just like a bumper pull but with a gooseneck. I know i have seen trailers like this before, but I cannot find any information on the web about what sized tubing to use for the neck. Any help would be great.