Quick check: you chose to file the ports so that you could use the 2.0 locating pins in the 2.5 head, correct? In the grassroots build they removed the locating pins and modified the mounting holes on the manifold (seems harder and higher risk to me).
What's the point of using a 2.0 runner? Does it flow better? I have a 2.5 and looking for stuff to do. Looks like nobody does anything. TB swaps or higher flowing intake idk
Your aluminum intake runners has no swirl flaps... (like they do here in Europe). Do you know if this is some sort of US-spec or is this an aftermarket manifold?
i also have a 2012 Miata with no engine in it, I did some little research but was advised to never try the 2.3 Mastung reason been that the higher fuel pump will touch the firewall,
