Thanks a lot guys, I really appreciated your help.
I believe I've found the intake leak. It's on the front intake boot, between the front Intake Manifold and the FLANGE where the Throttle Housing mounted is.
I've used carb cleaner, as I sprayed around the front intake boot the rpm changed extremely. I couldn't notice a leak somewhere else.
What else should I replace at the same time when I do the front profile gasket and which parts I do need except part#11?