I am not trying to knock the Trinity mill in any way shape or form... I am just curious of its specs... I run a CL7B as well have modified a few, the pictures of the trinity internals I seen are a dead ringer identical to the CL7B.... The case and carb are even identical, which leads me to believe the Trinity is based off the CL7B.........as for stroke, the Trinity i bet has a 16.9 mm stroke.... So untill you can show me a stroke of anything other then 16.9 mm I am going to say the Trinity mill is a rebadged CL7B......... Which IMHO is a wonderful motor and an awesome platform to build an engine line from... definitely one of the most powerful .21's i have ever run...