Velocity stack is an interesting part because there’s no way they are making them with CNC from a solid piece. You could probably cast a stack if you really wanted to, but more likely it’s just tubing that is molded over and tapered, though I’m not sure what kind of tooling you would need to reliably create such a part. In short it looks simple but it might not be. In any case thanks for the idea, I’ll see what the shop and the CNC programmer think, maybe they will have some ideas about how to make it as it’s certainly not the materials that are pushing the $50 tag.