A tubular manifold will give you best results with the individual piping setup. Ivory8g has one on his Galant and spool up response from the turbo was improved. The cast manifolds are a great choice as they are most resistant to high EGTs (Exhaust Gas Temps) so they won't crack like a welded manifold. Don't let this push you away from a tubular manifold though as most are tig welded and hold up quite well. You might want to check which one Ivory8g went with, I can't remember off the top of my head right now...
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