I like to cut those flush with the manifold and drill them out and run a tap through to clean it up. Cast iron is a lot harder than steel so the job is easy. That stud remover might get it out easily.
I like to cut those flush with the manifold and drill them out and run a tap through to clean it up. Cast iron is a lot harder than steel so the job is easy. That stud remover might get it out easily.