NEW BIG DOG S&S CYCLES FULLY POLISHED CYLINDER HEADS. P/N 91-1142 F&R. 4 1/8" BORE FOR BIG DOG 117 ENGINES. THESE WERE STOCK APPLICATION FOR ALL 2005-2011 BIG DOG MOTORCYCLES WITH 117" S&S SUPER SIDEWINDER PLUS ENGINES. ALSO FITS ALL AMERICAN IRONHORSE 4 1/8" BORE ENGINES, (111" 117" 124").
THESE FIT S&S S/A (SPECIAL APPLICATION) ENGINES ONLY. WILL NOT WORK ON HARLEY EVO OR TWIN CAM CYLINDERS.
BRAND NEW WITH GUIDES INSTALLED, (NO VALVES OR SPRINGS). THESE HAVE PROVISIONS FOR COMPRESSION RELEASES.