i took out my intake, plenum and runners yesterday and they have a thin layer of black sut build u inside, is this normal??? the engine is getting rebuild and i want to poss re-use these parts, can i just clean em??? and what is the black stuff???

Normal. Its a combination of things from fuel vapors to oil vapors to exhaust vapors coating the surface of everything from the TB back.

ok, thanks, i ll ignore it....

An oil catch can will prevent the dirty intake.

whats that and where can i get one???

A catch can is a device to capture excess oil from the PCV system before it makes it to the intake. It is very common with the 4th gen F and Y bodies with LS1 engines because they have a great deal of bypass oil picked up in the PCV system.

I have yet to see one used on a 3rd gen TPI but I am sure it's possible. Here's a link to one persons install of a nice, billet catch can on a new GTO. It's give you a general idea but isn't the only catch can available by far. Some people use an air compressor ail/oil seperator for a cheap but effective catch can. All cans capture oil so they must be able to be drained fro time to time.

http://www.redgto.com/KB/article.aspx?id=10001

The same thing happens inside LT1 intakes, carbureted intakes, 4- and 6-cylinder MPFI intakes, CPI/Vortec intakes, CFI intakes, and probably LS1 intakes - blowby or not. You can clean it out, but in a few months of use it will be back. Unless it is completely covering an EGR port, vacuum port, or the MAT sensor, it probably isn't harming a thing.