You can buy couplers with a 3/4" round weld on end on one or both ends of the coupler. They also make the couplers with a variety of sizes and styles for the other end of the coupler. You may have to buy the coupler you need directly from Borgeson, they seem to have the most options.

There is also a different splines end that fits Mopar boxes and racks, I just can't remember what size it was, for sure, but it seems like it was a 3/4 x 11 spline coupler end. Check the size of a Dakota rack end.

A round weld on end put onto a spline steering shaft end is asking for trouble. Get the correct end. Please. Gene