easy fix, done this before. you get a special arc welding rod that welds to cast iron. wind the amps up & get your mate to keep the weld area hot with the oxy acetylene or similar. you just build up a big blob that you grind into shape, redrill the hole & bobs your uncle it's fixed! a coat of paint & no one will know. i assisted a dirt track racer to do this exact repair, it's pretty strong!