Howling intake noise after new intake and TBI

So irecently put a new voodoo cam, performer TBI intake and holley TBI in my truck. Now i hear what sounds like a belt squeeling (but its not) after i release the accelerator. Example....give it gas, let off pedal and then there is a squeeling sound as the engine idles down and the sound stops as it hits normal idle....Is this normal? sounds kinda like a turbo its kinda cool actually....

Sounds like a vacuum leak at the TBI base gasket, or maifold to head. Is basicly the reverse of a boost leak. Vacuum is highest on decell. The noise is not normal and if your engine is idleing rough the leak is probably having more effect than the cam.

I agree might need to check those gaskets good. I know it is messy but some oil is one way to find a vacuum leak.

If you open the hood and remove the air cleaner, can you tell if the noise is coming from the TBI?

The reason I ask, is that I also have the performer TBI intake (on my 90 GMC K1500 5.7) and I had some issues with the power brake vacuum hose routing. When you let off the gas, the vacuum will be higher and your vacuum hose to the brake booster may be leaking.

//2000CAYukon

We removed the bracket that the brake booster line was connected with so it would hook up to the performer intake. It sounds like it is coming straight in from the air cleaner.......

So to check gaskets i rub some oil along where the manifold gaskets are and look for bubbles?

turn truck on. get starter fluid in a spray can (duh). spray until the idle changes O.o always worked for me. where you spray the starter fluid is where the engine is sucking. (duh again). hope this is some sort of help.