Im not an expert on turbos, but the fact that it originally had crap piping and leak problems, id want an independant mechanic to look into that. Id also find out if 4 psi is all that the turbo has been run at, those engines arent the strongest in the world when boost is applied. Ask for some pictures to post here. And I would say if your interested make a day trip out there to look at it, it should at least be a pretty fun test ride.