Flowtech LS Swap Exhaust Manifolds - Natural Cast FinishThese Flowtech cast iron exhaust manifolds have a 2. 25 inch outlet, natural cast finish, and are designed to hug close to the engine block so they fit into a wide variety of replacement and engine swap applications at a budget friendly price. Being cast iron means they will provide years of leak free performance with less under hood noise than traditional headers. Plus, their shorty design means you can route exhaust tubing close to your frame floor