No Engineering required for engine upgrade like that - as long as the power isn't increased by more than 150% it's a free for all. The only thing Vicroads worry about is that the engine was available in that model. Upgrades to the fuel system are actually looked at favourably - they like old cars with EFI. Your allowed to upgrade to later specs, just not allowed to go backwards.
You can turbo or supercharge as well, as long as the power increase is within what is specified. Outside that, you need engineering to prove the chassis and brakes are up to the task.
SA mods and Vic mods are chalk and cheese - totally different systems.

