Hope you can stand another "compression test results" thread
In my opinion- I have seen engines like yours before where they have a large variance in readings. You do not have burned valves - the pressure in a burned valve cylinder would be much lower. The lower cylinder pressure cylinders are on one bank, #3 and #7. The only reasonable explanation is uneven cylinder sealing requiring honing, piston fit, rings, etc. You should look elsewhere for a loss of power.