S&S, SuperStock exhaust valve, 1.575" diameter - 99-17 Twin Cam with S&S 79cc SuperStock heads; 84-99 Evo B.T. with S&S 76cc and 82cc SuperStock heads with flat top pistons (NU) 500576 To be used as a

To be used as a OEM style replacement item for use with internal throttle control and handlebar controlled ignition advance

• All outer housings are coated with a non-yellowing clear covering for abrasion resistance

260mm Center width

Classic look with block thread pattern

In 1984 H4 was finally approved and introduced

S&S, SuperStock exhaust valve, 1.575" diameter - 99-17 Twin Cam with S&S 79cc SuperStock heads; 84-99 Evo B.T. with S&S 76cc and 82cc SuperStock heads with flat top pistons (NU) 500576 To be used as aReplacement for S&S Twin Cam 531829 531830 531833 531834 79cc SuperStock heads and for S&S Evo B. T. 76cc & 82cc 512522 512523 531904 531905 531906 SuperStock heads.