Supposed to be a 25-30 hp boost. Best results are from advancing it 8 degrees from where the factory installed it (121 ICL from the factory, should put it in at 113, cam has a LSA of 117). I'd definitely put headers on it to get the most from the cam, the stock exhaust manifolds are TERRIBLE! Does that year of Durango share the same frame/platform as the similar year Grand Cherokee? If so Jeep SRT manifolds would be the way to go. You also need 6.1 exhaust springs for both intake and exhaust and 6.1 pushrods.