only difference should just be the bracket that is welded on them where the threaded end of the limiter strap adjuster goes thru. They are welding up an inch higher then others.Well at least the SXR ones are welded lower,I have mixed them up and used both on my SRX.Side by side they are identical otherwise..now a viper could be different..don't know.Check the parts fiche..but don't know why they wouldn't inter change..what do I know...lol