Valve covers are machined from one piece of billet aluminum, They are machined to clear all rocker arm and spring combinations, Angled machined to direct oil onto the valve springs, Black Anodized finish, Designed for Sprint cars with SBC engines with 12 to 23 heads. Billet Small Block Chevy Valve Covers, Sprint Cars, Black Anodized. Speedway Racing Engines billet SBC valve covers. Fits 23, 18 and 13 degree heads. Designed for Sprint Cars. Fits SBC engines with 12° to 23° heads. Speedway Motors is America’s Oldest Speed Shop® and has been a trusted source for specialty rodding and racing products and friendly expert advice for more than 71 years.