stock boost evo8
There is no exact number for each gear, and not all VIIIs are the same. You need to specify the year.
We've already said about 1000 times what stock boost is for Evos, though:
03/04 - 19.5psi@3500rpm tapering to 16psi@6500rpm
05/06 - 20.3psi@3500rpm tapering to 17psi@6500rpm
Higher gears have more load and thus usually see a higher spike and higher sustained boost while lower gears don't have enough load to see full boost usually.
We've already said about 1000 times what stock boost is for Evos, though:
03/04 - 19.5psi@3500rpm tapering to 16psi@6500rpm
05/06 - 20.3psi@3500rpm tapering to 17psi@6500rpm
Higher gears have more load and thus usually see a higher spike and higher sustained boost while lower gears don't have enough load to see full boost usually.