This is Indy tunnel ram without cover after initial cleaning. I was thinking about spacer under top cover but this is for future experiments. No room for anything in current setup.
I was asking about filling that void based on this plenum design.
OK sorry I misread this reply. So what i have in that cavity is sloped in a similar way but, more importantly let's not assume that Indy designed this 'correct' either. You won't see all this 'correct' executed in any new tunnelram plenums.