Brodix delivers the industry's most powerful and durable Out-of-the-Box LS head in it's class with their br series. The ''br 7'' comes standard with 72Cc combustion chambers, bowls blended, and intake ports matched. The ''STS br 7'' is a 100% CNC ported version that flows over 375Cfm. The ''br 7'' and the ''STS br 7'' both utilize a 12 degree valve angle and 2.204''/ 1.614'' valve combination. The ''STS br 7 273'' flows over 415Cfm with a 72Cc combustion chamber and 2.250''/ 1.614'' valves. The br-series heads feature the ''6 head bolt per cylinder'' LSX block design but are standard LS block compatible and accepts standard LS7 valve train components. The 6-bolt LSX design easily and reliably handles increased cylinder pressures of turbocharged, Supercharged or high compression applications. Every casting is poured from a-356 virgin aluminum and d before Brodix utilizes their in-house processes such as CNC machining and heat treating to assure that you receive the best products for your hard-earned money. Solid, phosphorous bronze guides are used to reduce valve leakage and oil consumption. The ductile Iron valve seats are installed for use with unleaded fuel. Sold in pairs.