These only have maybe 2 hours run time, basically brand new, they are completely fabricated and ready to bolt on to a big block Chevy jet boat with a 12JG Berkeley split bowl pump, comes with gaskets, bolts, exhaust Hoses everything needed to bolt right on. Through the Transom exhaust Hoses are 3.5 inch. I ran them dry, I do have water injector kit, I changed my interior design and can't have headers with inclosed engine. I am putting stock exhaust back on.