Exhaust Manifold Identification and Replacement Guide
When replacing the exhaust parts (manifolds, risers, elbows) on your marine engine, the best way to make sure you find the proper replacements is to look at the your current exhaust parts and write down the casting numbers from each. In some cases the casting numbers may be on the engine side of the part, making it difficult to see prior to removal.
With the casting numbers handy, do a search for each one to see if a compatible part is available:
If nothing comes up, you can also try the Sierra SONAR tool, which matches OEM and aftermarket part numbers to Sierra parts.