Extreme Billet Chevrolet 2-Bolt to 4-Bolt 400 Main Journal Main Caps Precision CNC machined from superior quality low carbon 1020 billet material. Available as stock replacement (straight bolt) or with splayed outer bolt holes. The splayed caps feature 10 degree angled outer holes to positively reinforce and tie the block together. Main cap set consists of the center 3 caps. Front and rear caps are also available. Use together for ultimate in bottom end stress and flex management. Drill bushings included with caps requiring them. Side notches for easy removal. Proudly 100% manufactured in the U.S.A. Line boring required after installation.