Mag housing

Hi
can I use a sil 200 mag housing in my small block engine casing and if so, do I need to alter any thing? Mine's damaged and needs replacing, I have a new sil GP 200 housing that I could use or should I try and get hold of a small block housing?
noob here so all advice gratefully received, cheers.
can I use a sil 200 mag housing in my small block engine casing and if so, do I need to alter any thing? Mine's damaged and needs replacing, I have a new sil GP 200 housing that I could use or should I try and get hold of a small block housing?
noob here so all advice gratefully received, cheers.