S&S Cycle SS90-1004 Super Stock Cylinder Head Kit Natural Aluminum Finish for Harley-Davidson Big Twin 86-99 (requires S&S 3-1/2" & 3-5/8" Bore Pistons) RM-Z 250 2008-2009

RM-Z 250 2008-2009

Clutch T/Out Brg

• D-Ring Retention System

should a puncture occur

S&S Cycle SS90-1004 Super Stock Cylinder Head Kit Natural Aluminum Finish for Harley-Davidson Big Twin 86-99 (requires S&S 3-1/2" & 3-5/8" Bore Pistons) RM-Z 250 2008-2009These S&S Super Stock cylinder heads for 1984 '99 HD Evolution Big Twin engines feature a specially shaped combustion chamber and require special pistons that must be purchased separately. (Not compatible with stock style flat topped pistons) Large 2. 000" intake and 1. 605" exhaust valves and high flowing ports supply plenty of air for big inch engines. Compatible with cams with lifts up to . 650". Compatible with stock 3 1 2" or 3 5 8" bore engines.