I just installed the Cobra Jet Intake, a Super Cobra Jet monoblade TB and the JLT CAI. Under 1/2 or 3/4 throttle there is a very high pitched whistling sound, is this normal?

Mod list.

JLT CJ CAI, FRPP SCJ Mono TB, CJ, Lethal X, Axle backs

It actually sounds more like a squeal than a whistle.

 

You posted this on svtperformance...right? Normal once again. Your car is ok.

 

This. The install of the CAI alone would result in increase intake noise/whistle. The factory systems have baffles in the intake to quite the noise. The aftermarket ones remove this baffling for more airflow but more noise.