Okay heres whats happening
At idle and sometimes higher, in park, u can hear this light grinding noise, that is notable from the inside of the car, i put my scope to the nose cone, i couldnt hear the grinding any louder. Also i checked the oil in the */C it is full to the bottom of the threads.
the sound will just dissapear, then if i rev the car up, it returns.
Any ideas?
ALSO the noise is without a doubt coming from the front of the engine as in were all the pulleys are, almost sounds like its in the water pump area..

Try putting the car in neutral or applying the parking brake before you put the car in park and see what happens.

Try using a piece of heater hose next to your ear or a mechanic'* stethoscope while the engine is running. If that doesn't pinpoint the noise, you can remove 1 belt at a time and run the motor for a few seconds to see if the noise is gone. You can even run the motor for a few seconds with both belts off to see if it'* the crankshaft balancer (I had to do that a couple of weeks ago).

Once you isolate which belt drives the noisy part, spin each part by hand with the belt off and try to listen for unusual noise.

I like the hose idea!

Bunch of hosers!!! (Canadians will know that one, eh Bob and Doug!)

A wooden broomstick handle or any similar piece of wood works well, too.

the idler/belt pulley is proably the problem

this is the fifth tensioner assembly for the SC it has gone through, i have an old one, i will try that one tomorrow, also in drive at a stop it has about -8lbs of boost on the gage were as it was around -10 befor..

Today i went to start the car, i heard this squealing coming from the engine compartment, so i opend the hood, and right away i could tell it was the SC tensioner, so i dug out the original tensioner and installed it, problem solved, but why the hell does this car eat tensioners!? My teacher said most SC'd cars have mechanical tensioners that lock once you've adjusted them..

Well, you've really only got two possibilities for the source of the squealing: a bad bearing on the pulley or a misalignment between the tensioner pulley and the others (which may cause the _belt_ to squeal, and eventually the offset loading on the pulley bearing can cause the tensioner to fail as well).

Okay, _three_ possibilities, if you want to include a cat with its tail stuck in the tensioner...

No, I think he'* thinking of timing-belt tensioners, for which you'll frequently adjust an offset bolt mounting until it'* tensioning the belt to some certain amount of deflection, then lock it down. On the Bonneville (and in fact most GM cars with external serpentine belts, in my experience), the serpentine belt tensioners are spring-loaded, not locked down.