Change of engine number

[fordOwner]

G'day forum correspondents.

I'm in Perth and I have changed the engine in my ute.
I have downloaded a form from the department of transport to notify them of the change however the form states: "If the configuration of the engine has altered to the extent that the number of cylinders, RAC horsepower rating or fuel type has altered then the vehicle must be presented for an examination and a certificate of inspection completed.

I have replaced my stock xh motor for an EL XR6.

I take it this would be a change in horsepower rating?
I have heard that an increase in horsepower is considered to be 25% or more.
Anyone else heard of this? Would the XR motor be considered 25% more horsepower?

What do you guys reckon? Should I fill the form out and post it? Or will I have to pay mr plod a visit?

Cheers.