part 1 r31 skyline drift car

so me and a friend went half's in a old Nissan skyline r31, we got it for $300 but ti need a lot for work. the first thing we need to do is get a exhaust system, the previous owner, had removed the old exhaust system with a angel grinder, so it can't fixed. once we have the exhaust system we can tune it, and see if the engine is still good. the engine we were told has had a rebuild but it is not running right. when we toke it for a test drive. but we can not tune because it makes too much noise.