RZ-57 Helmet Size:X-Large BMR recommends a 10-inch spring

BMR recommends a 10-inch spring for spring rates 150lb/in or less

Drag Race/Oval Track 276/284 Solid Roller Cam for Chevrolet Small Block

Compatible with GM part number 10379038

Making it a popular addition for performance cars

a minimum weight reduction of 42 pounds is common

RZ-57 Helmet Size:X-Large BMR recommends a 10-inch springThe Zamp RZ 57 helmet combines the latest Snell SA2025 helmet technology with the best value in the market! This model provides minimal front venting with the option to add a Top Air accessory to run a Forced Air systemkeeping you cool and helping prevent fogging in extreme racing conditions. Inexpensive is redefined with the RZ 57, offering features and quality comparable to helmets that cost twice as much. Built for racers who demand reliability,