Factory cast iron exhaust manifolds were never worth a damn at doing much on any performance small block. They look ugly, don’t fit with aftermarket heads, and they have such small ports that they never flowed enough to be of much use. This is why every hot rodder on the planet looks at headers as one of their first performance upgrades. But are headers always the right answer? Not always. Headers often create fit issues, can be a problem for cars that are lowered, and require more maintenance and upgrade parts in some cases. A high flowing cast iron exhaust manifold that looks nice, fits great, is available in multiple port configurations and coatings means that these are a great fit for hot rods and muscle cars of all kinds.
These are perfect for the car you want to drive regularly, never have to worry about, and that you don’t want to fight with fitments because of your accessories and such. I like these for a cool custom cruiser, truck, or ultra low ride. But they do flow as well! Maybe not like a 1.75 inch equal length header, but with 1.625 inch ports and 2.5 inch collectors they are ready to attach to your aftermarket exhaust for a great sound and performance. I’ve got a couple projects that could have used these!