When mine failed I used a vibration resistor u-joint from Flaming River. Had to grind out a few of the splines on the bottom side to get it to mate with the steering rack, but I don't have any more steering issues. I figured this is one of those "get it updated and make it safe" parts that didn't need to stay original. The down side (which i haven't bothered to fix yet) is that the horn doesn't work anymore. The u-joint is about 1/4 inch longer than the original unit, which causes the steering wheel to sit up off the horn electrical contacts. Haven't figured out an elegant solution yet...
