This Performance EL series test kit allows the flow bench technician to test Harley Milwaukee 8 cylinder head on YOUR flowbench. The kit contains the following items. Performance EL series VOF fixture test kit Part No. DEL-VOFHDM8 Milwaukee 8 cylinder bore fixture (3.937″ std bore) Part No.DEL-HDM83937 1-3/4″ O.D. flow test pipe 9″ long, hardware Part No. DEL-FPHDM8175 (Upgraded to a 4.250″ cylinder bore add $55) Please e-mail with questions.