Frame ties, If you got a fiberglass body don't leave home without them. I have seen these thing in alot of variations, some good and not so good. Now I don't proclaim to be an expert, or posses any mechanical engineering knowledge, but some how I don't think a section of 1 1/2" pipe welded to the side of the frame is going to do much to save your ass in the event of a roll over. This is my kids life on the line. After much thought on this subject we decided to go with 2 x 3 x 1/4 wall rectangular tubing. Maybe a little overkill but I don't think so. I took an adjustable bevel gauge to get the angles and transferred them to cardboard, made some adjustments then transferred these to a piece of 2 x 3 wood. Kept tweaking the angles on my radial arm saw then finally put it to metal. All I did was cut a v shaped section at the bend, not cutting thru the one wall, that way I wouldn't have to rely totally on my weld. Just heat up the area of the wall and bend close and weld the 3 remaining sides. The decision was made to notch the end to fit to the top outer corner of the frame, that way any force would have to be transferred down and in on the frame rails, thus literally having to collapse the frame rails rather than a shear force if they were fastened to the outside of the frame. I would rather have the frame take the force and work for me versus a weld to the side of the frame rail. The passenger side tie also had to be clearanced for the fuel filler hoses, so I simply cut a section of 1 1/2 pipe and layed it in the corner of the tie and weld. 1/4" plates are then welded to the top of the ties and bolt directly into the rear roll bar mounts. Hopefully these will never have to be tested, but at least give us piece of mind knowing we went above and beyond.