sorry I did not reply fast enough but there is 13 hours or so between my place and the US.
we have the RWD lumina from HOLDEN australia(as well as the caprice which is also a RWD). by the way there are the coupe, wagon, 1tonner(pickup!) from that lumina but we do not get those.
anyway, the engines are twins from the outside(I do not know about the mounts) I think I should try australian forums or so.My engine has a spun bearing and I thought of getting a fresh young engine instead of fixing an old motor(fixing costs around 800$ here)
Guys,Try to search for hot rodding life in australia. That lumina comes with an LS1 V8 (comming in the corvettes) in the SS trim, THAT engine gets modefied to a 427 cubic inches and 600 Hp (that is NA!!).