Popular “short style” water pump that was originally used on pre-1969 small block Chevrolets. Pumps are built using all new components and an aluminum body for added weight savings over original cast iron pumps. Pump features a 3/4" main shaft and bearings with a 5/8" pilot and a billet steel hub drilled for both small and large fan bolt patterns making this a good choice for street and mild performance vehicles. Block mount to fan hub dimension is 5-5/8". *This pump is not recommended for use with mechanical fans over 5, 000 RPM. Above this RPM, use the ALL31105 pump with a 3/4" shaft/bearing. Note: Water pumps may need to be clearanced for use with 8" dampers.