oil leak

I have a 95 lumina LS with the 3.4L DOHC and it has an oil leak for awhile now...weve replaced a few gaskets here and there yet it still leaks, anyone know of some common leaks on this engine so i can check around some more

There is an o-ring seal on the oil pump drive shaft that is very common to leak. It is located on the drivers side of the engine, under the throttle body, in the center of the "v". It is essentially a distrubutor with the top cut off. The o-ring is Fel-Pro part #70800, and I also put a #70194 small block Chevy paper gasket in there for added insurance against future leaks. Both gaskets should cost less than $4.