You can add 17 HP from the 330 HP if you also upgrade your camshaft for $4100 gaining a total of 347 HP for $15000. I would trust Kleemann to do my upgrades since this is solely what they do most- Merc mods. You may find it cheaper in the future in a do it yourself kit but your engine's lifespan depends in how well you mod your car. Just my 2 cents