A big block making real cylinder pressure puts more heat through the exhaust valve than a standard stainless piece can shed indefinitely, and a valve that gives up at the seat takes compression with it. Inconel holds up to that heat and pressure cycle after cycle instead of fatiguing at the margin.

AFR 7633-8 Inconel Tulip Exhaust Valves Features:

• Fits big block Chevy applications
• 1.880 in. head diameter
• 11/32 in. stem diameter
• 5.450 in. overall length
• Swirl-polished, undercut stem
• Dished, tulip-style head
• Inconel construction resists oxidation and heat
• Set of 8