Pitman arm problem

I'm swapping out the steering box on my 64 dart. They are both power steering units. The old box is Part # M2127008 and the "new" one is #G3643012. My problem is the shaft for the old pitman arm is 1.125 and the new box is 1.250. Is there an interchangable arm I can bolt onto the 1.250 shaft and still be able to hook it up to my stock center link?