So yesterday I got a dsp5 switch with 400hp/500hp/600hp/1200rpm/stock tunes. My tranny is rebuilt here in Norway in one of the two shops that are recommended from the Duramax guys over here. So we set it to 600hp and went for it.. it’s really fast with no trouble in the tranny and the engine seemed like was doing great! The tune has around 520-530rwhp I would think. There where some black smoke that’s for sure but not near the worst I’ve seen So stock motor, stock fuel, stock turbo, 4” exhaust, boost value making engine HP.. can that be safe??