This is a starter kit for flow test LS2 cylinder heads on your flowbench. It comes with are budget Performance series valve opening kit. Works on 241,243,317,799 casting will not work on LS3 heads. Kit includes valve opening dial indicator 5/8 hex nut threaded 7/16-20 5/8 hex nut threaded 3/8-24 5/16″ rod 4″ long (2) 5/16 swivel clamps (2) flow test springs LS2 inlet flow guide LS2 1.750″ o.d. flow pipe LS2 valve opening adapter Please e-mail with any questions.