S. B. International has put together the most comprehensive and accurate Valve Spring Specifications listing available today. Each spring has been tested to provide the latest information available. In some cases the spring specifications may have changed from those originally installed in the cylinder head. Where possible we have indicated in the applications section where a spring can replace an earlier version or where some casting modifications may be required. It is also not safe to assume that the test specifications represent the actual spring installed height requirements. Although this is true in many cases it is always recommended to check installed height requirements against the OEM specifications.