ARP Hi-Performance Series Head Bolt Kit - SB Chevy - BRODIX -12 - 18 Degree -10X - Hex Heads 23011713 spread port headers are required

spread port headers are required since the center ports are spread further apart then stock GM products

Integrated channels in face piece offering multiple options to install drinking tube

580 in Guide

5-1/8 in Flange

our fully-adjustable

ARP Hi-Performance Series Head Bolt Kit - SB Chevy - BRODIX -12 - 18 Degree -10X - Hex Heads 23011713 spread port headers are requiredHigh Performance Series Bolts are rated at 170, 000 PSI and available with hex or 12 pt. Heads. Kits include parallel ground washers. Since 1968, ARP is the fastener of champions and the world leader in fastener technology. Product Description: Cylinder Head Bolt Kit High Performance Series Hex Head Chromoly Black Oxide Brodix 12 Rollover 18 Degree Head Small Block Chevy