y brake booster has always hised when I'm on the brakes. Sucking in from the interior, goin into the booster itself. but the booster/reserve will hold a vacum after I shut down the engine. So I replaced the booster with a perfect condition one out of a 9' K5, still does it but not as bad. Sometimes it's perfect, usually after some decelerating where the manifold should be greatest. So it got me thinking that I might have to much cam and not enough vacum? Would it cause these symptoms? The brakes work, alittle spongy, but the noise is annoying. And yes I have flushed and bled the brakes. Cam specs (off the top of my head) 214/216 dur. and .464/.468 lift Displacement, cubes, and did you say you drive a riceburner???