i dunno where u r from but i was looking on the rta website and it states that u actually can not have anything done to your engine to increase the engines performance while u r on your P's. but im not sure because i have only heard about not being able to have a turbo from mates of mine. but im not 100% sure so driving a 1200 ute with an engine converstion might be ok.
but yeah not 100% coz i have been trying to work this out myself.