Chevy BBC 454 1.880" +100 11/32" Stainless Steel Exhaust Valves The main difference is that

The main difference is that there is an open area under the plenum chamber

These banners are made of weather-resistant polypropylene

then highly polished and chrome plated for lasting beauty

efficiency

It also features nitrous bosses and rear water ports

Chevy BBC 454 1.880" +100 11/32" Stainless Steel Exhaust Valves The main difference is thatWhen it's time for valves, don't cut corners. Get genuine Speedmaster stainless steel valves. They're made from a tough, stainless steel alloy and are carefully designed to increase gas flow for more power. What's more, they have hardened stem tips for durability and are swirl polished.