Engine changes are classified as an "owner certified modifications", even if it's just a direct engine swap. If you were keeping the same block then this wouldn't be an issue since your engine number doesn't change. Just to bear in mind.
For owner certified modifications, you have to fill out an "Adjustment of records" form and attach it along with a blue slip, so yes you will need to obtain one.
Usually if you get a shop to do the swap for you, you can take the original rego and engine swap receipt to anywhere and they shouldn't give the car a too rigorous inspection since your documentation is in order.
Full document is here:
http://www.rta.nsw.gov.au...fications_nov_2007.pdf Owner certified modifications are still a big grey area because stations that do blue slip still don't quite know the rules themselves of what is owner certifiable, and what requires an engineers certificate. Like for like engine swaps should be straight forward though.
I know of someone who has done an NA for NA swap on an older car, but newer generation engine which is actually a capacity decrease and power is within 15%, all OEM emissions and ECU and ADR approved, struggled to get anyone to blue slip it as an owner certifiable modification.