hi, im in the process of buying a 8p stage 2+ but theres no paperwork for any of the uprated parts. i can see a full milltek and big induction filter and the car seems to go well but how do i know if it has a hpfp fitted making it only a stage 2? do they just replace the internals or the whole thing? is the standard one made by hitachi? what do i need to look for? thanks...