1E-2E-3E exhaust outlet measurements for 3D flange model

[EP70-PT]

I'm trying to make a solidworks (CNC) model for a 2E exhaust flange for custom headers, I have the gaskets for dimensions but I need this measurement:

If someone with easy access to the head or the heatshield could measure this and tell me, it would be great (distance between the exhaust ports)

I'm thinking about something like this for the flange but I need the correct measurement for the reinforcement in the middle:

This design might be easier to make:

EDIT: Done a rough prototype, no exact dimensions yet:

Edited March 1, 2015 by EP70-PT