Im thinking about selling my 906s. They were off a good running 383. They have since been gone through and have had hard seats put in, viton seals, valves upgraded to 2.14/181, gasket matched and ported. They have not been run since finished. The valves have locks, but no retainers or springs because I dont know what cam your running. Im asking $500 plus shipping. Email AmoB64@msn.com or PM me on the board. Thanks!