1995 Holden/GM 304 efi V8 American equivilant?

Im in Australia and I own a Holden (subsidiary of GM) commodore with a 304 fuel injected V8, its a 1995 model but i know the same motor was used from 1990 - 1998. I ume it is some sort of Chevy block. Now i am trying to do some work on the heads and i am not getting a great selection of performance parts here in aus that are reasonably priced. So i would like to know what is the American GM equivalent motor(if it exists at all) and what cars did it come in. Hopefully then i can find a larger selection of parts to chose from. Thanks.