Oh my gosh, while perusing my aircraft knowledge stuff I went to one of my favorite experimental aviation companies Great Plains Aircraft, and saw these..
http://www.greatplainsas.com/llc1.html
Sorry guys, guess the hyperlink did not set--but check them out--with the new advent of super tough all aluminum T1 engine cases, along with billet cranks and all the best equipment for cheap for these engines--these heads would make monstrous power!! No overheating!!! This kind of stuff is really cool!