All of a sudden I have been noticing this lil knocking noise ( ticking if you will). I fill up with Amaco 93 octane gas as I always have. The mods are in my siggy. I know with the plenum there is a harmonic note to be heard but it is diffrent then that. But the noise im hearing is just about the same db as the hormonics from the plenum. I know what the flywheel sounds like and it is not it either. I believe the trans is bad once again ( Cluncks into gears ) and will get it replaced as soon as I order my Nismo clutch. Could this noise come from the trans?

Someone with good mechanical experiance please give some ideas as its realy starting to worry me.