some cracked steering boxes will be found with multiple cracks with some around bolt holes. so there also may be some machine work needed after welding. If you can find a shop familiar with auto racing casting repair would be best. Other wise clean well. maybe bake out grease. find a competent welder. the material is likely easy weldable alloy A356.
search this forum for other ideas and consider adding a reinforcement.
Ken Geiger, Toronto
1965 GTA, RHD, Stradale
ex- 1965 GTA, RHD, Corsa, Trans/Am 66-72
1964 Sprint GT, B-Sedan in 70's
1970 Giulia Super (CDN Spec)
1976 1600 GTj (Italian Spec)
1966 Harley Sprint (Aermacchi) 250
2000 Catalina 320, Hull #765 Northern Dream
2001 BMW Z3 3.0i