This is a solid model of a header flange for a P90 head.
The file formats are STEP, and IGES. I can post in other formats if you would like, just PM me and I will save my file in
something you can use.
Also attached are some solid models for a header design. This isn't the one that I went with, but it still looks pretty
cool. Note that the flange is attached upside down and uses the wrong bolt pattern for the middle flange (my mistake). Use
the flange only file for flange dimensions.