Welcome to CHR. I'm not sure that it's relevant, but the first thing that comes to mind is that you have no gap at the "china wall" block to intake surfaces front and back. If your Edelbrock intake is sitting too low and actually riding on the block surfaces then the intake to head surfaces aren't going to seal, and this would be made worse if you're using rubber gaskets on the china wall seal. Just my thought, and it may be bogus.