Bill Mitchel Products. About $5800 plus another $900 to do the final machine work. They are light Mine weighs 144 with caps on the mains. They also come with a GM bolt pattern along with the Mopar pattern. Bronze bushed lifters with oil holes for oil through pushrods. 4.500 bore, dry sleeves, priority main oiling, accept standard oil and water pumps, bridges in the valley for strength. The bores came at . 015 undersize, and a lot of honing was needed also for lifters. They come at about . 902 size.