I did this on a RR many moons ago. I cut two pieces of 2"x3" 1/8" and measured back from the transmission cross member to the hole on the stock spring mount. I took the hangers off measured the length and cut my pieces of 2x3 my first measurement minus the length of the hanger. Then I welded the hangers to the tubing. I then cut the bottom out of the frame rail and cut the hanger into the rail untill the tubing touched the transmission crossmember. Welded it to the crossmember and the frame rail. It looked a whole lot more factory than what they sell and I bet stronger too.