I was wondering if it was possible to take a Briggs flat head in the 3-4 hp range, bore out the block and press in a sleeve that would allow for a huge overbore. I haven’t had one of these engines in many years,so please forgive me if I don’t know the limits of what could be done. Has anyone considered doing this? The advantage, in my mind would be to have a small frame engine with a much larger displacement, that would easily fit a small frame mini bike. Jay