1995 Buick Century V6 3.1 engine leaks oil from under the rear of the intake manifold. Could the rear intake manifold gasket be defective?

gm made defective gskts,plastic and rubber,then they finally came up with decent gskts in the 3rd generation,they are metal and rubber,and available at most auto stores,sometimes they will sell you the old style,open the box and check,the full kit comes with v/c gskts and o-rings,want to get it right because the job takes 4-5 hrs to do right.

Thanks for the reply, I'll make sure to get the correct gasket kit...Once repaired I'll let you know how it worked.