Many places on this site it'* posted that if you aren't supercharged you should read about the upper intake manifold
This thread is stickied at the top of this forum http://www.bonnevilleclub.com/forum/...ic.php?t=28226
The plastic intake is technically a composite (yes..basically plastic).
Sorry to hear about your intake failure, the parts alone (including lower intake gaskets) cost about $250 and the job takes about 5 hours. This includes changing the lower intake manifold gaskets with aluminum frame gaskets from the dealer.
***Have the lower gaskets changed when the upper manifold is changed or you could have them leak as well***