If you are talking about my engine I think back in 2008 I laid the head out for a 1008 felpro gasket as I ran those up till my last two builds. So to simplify things it’s a .030 over 360 (4.030) so Cometic recommends a .030 bigger gasket to bore size. So my chamber again is probably because it’s on my engine reworked for a 4.180 chamber size running a 4.060 gasket. I don’t mind answering questions but please try to really take time to ask specific questions. In this post especially because of all the heads involved.