Do you have experience with either of them? If not your point remains irrelevant.spaks its a very good brand. i doubt theyll crack. those things are made tough.
cast iron manis look f**ken ugly.
I've never had sparks header nor turbo mani but my my bro have used sparks turbo mani on boosted ls/v and his using spark header on his k right now and the things look massive make lots of power.Do you have experience with either of them? If not your point remains irrelevant.