I started with a Rev9 TX-50E-57 turbocharger by recommendation from friends as a cheap turbo that matched the Treadstone 2.5” downpipe for Spec V. I used a Treadstone Replica Turbo Manifold off eBay. It needed the ports opened up a good bit. The port for the Turbosmart WG38 GenV Ultragate 38 was way too small and would probably have caused boost creep. The port matching doesn’t have to be great for turbo applications. You want to shave down any obvious restrictions. Be sure to clean out the metal shavings when finished. Went to Full Race inconel turbo stud kit

Nissan OEM m10x1.25 manifold studs