I could also use nickel filler rod and tig weld it I believe. I'll have to give airgas a call tomorrow and see what they think is best.
What steel did you use? 1045?
I cut the taper off the steering arm and trashed that part then butt welded the mild steel to the end (with the hole in the steel for the heim bolt) then for safety I laid a strip of mild well over the cast and out on to the mild . Remember you can put that outer end at ANY point you want... if you need it up or down... now is the time to move it so it lines up better with the rack height I used a hi nickle rod(I forget the number for it)