I agree with A.J., there is no way that your LA will turn an 11 x 7. I use to turn a 11 x 6 with my FX of the same displacement. I would suggest you go with 10 x 6-7. Running lean will get you in trouble but anyone that has tuned an engine should be able to run it right without having it lean out.

I think the cooling could be a problem. If you have it in a full cowl, it will overheat. Use to happen to my engine all the time!

First thing, though, try a smaller prop and ensure there is good cooling!