Shouldn't matter as long as it's a V8 that was an option for that model.

But I know what you're thinking. I once had a friend that put a 6 in his Torana (originally a V8) and was given a huge run-around by the RTA. One inspector told him that because it had a V8 originally he couldn't fit a 6 without an engineers certificate! Sanity eventually won, but my mate was a nervous wreck dealing with those idiots.