U need to register the number with JPJ, u need custom letter etc, some because of changes in cc
otherwise its illegal, worse case scenario when involved in incident the Insurance will check ur engines number dude !
If JPJ caught u surely SITA !
If Police, suspect for stolen engines -SITA !
if you dare just go ahead, i did it....off course you car have to be a sleeper
if your car mods to attract the officers - do think twise