.45 k&b mounting - how to mount

[geish]

I have a piper j3 cub and I'm preparing to mount a k&b .45 engine. I can either do it right side up or upside down. If I mount it right side up, the engine will stick out of the cowling. If I mount it upside down, all parts of the engine except the muffler are within the cowling. Is there a problem with all parts of the engine, including the head, being inside the cowling. Will there be cooling issues? I can put holes in the front of the cowling and use it as a ram-air type of air induction in the cowling but will it be sufficient? Also, are spinners important, or is it mostly for aesthetics? I prefer mounting the engine upside down for aesthetic reasons(the head is not sticking out of the cowling).