I massaged a Hatori header intended for the OS 160 to do this job. Didn't know that Hatori already has a header for the 33GT, which is great news. Papa you would need the 2301 header. I used the ES40G pipe but the ES30G would work fine. Distance from center of head to baffle was set at 28" similar to the SAP 180HP I've been using.

Fuel is Aviation gasoline mixed 50:1 with Bel Ray MC1 motorcycle racing oil ....100% synthetic. I use Aviation gasoline because of no smell and stability over long periods. But no reason why premium gasoline for cars wouldn't work.

Before getting ahead of myself, I really need to get the engine in the air and see what the performance is in a real application. Stay tooned