Does not work with raised port heads. Breaking in an engine with ceramic coated headers WILL result in damage to the coating and will VOID all warranties. Ceramic coated headers require several heat cycles to fully cure before they will withstand extreme heat. Hooker recommends using cast iron exhaust manifolds or old headers to break in new engines to avoid coating damage. Please call Hooker tech service at 270-781-9741 for additional information regarding ceramic coated exhaust products. The use of header wraps can cause the header tubes to crack or rust due to excessive heat and moisture build-up. Hooker does not recommend the use of header wraps as this will void the warranty. Hooker long tube headers do not come with header reducers. Factory style big block frame stands and motor mounts must be used to ensure proper engine locations and header fit. Many aftermarket mount brands relocate motor location which causes the headers to hit certain components.