hi Steve, i don't know what the difference between your longstroke star twin is and mine, eng # ZA7 8280, but mine has a two part rocker cover and i assume (this can be dangerous) that if yours is also two parts it will have the same profile as mine. I also presume that the head gaskets on all the longstrokes are the same but it would pay to get confirmation on that. As mentioned in previous posts you need to specify what thickness you want. Regards, Ben