Quote Originally Posted by dorikin View Post
no such thing as a 25% displacement increase threshold and never has been
Correct - and I vaguely recall the rules something along the lines of IF the engine you want is offered in your chassis at the same emissions bracket or later then it comes under "replacement engine". This is used to work out braking force required too.
Anything else requires proper engineering and hence illegal for platers. I'm yet to see a k series swap driven 100% Legally by a p plater ? ( or anyone for that matter lol)