OK, went flying with the El D, I have the hemi-head with two head gaskets. I am running a 10x5 old TF prop, muffler and 7% N, 27% (50/50)oil, long Fox R/C plug. First flight was a bit lean. Second flight got it fairly close, it started out just about perfect but near the end got lean. Looking it over once I got home I found one of the tank kick-out shims worked its way out and the tank was flat against the outside fuse. This causes some of the lean run. I'm thinking I want to go back to the original Fox head with one extra head gasket. This was the original setup I started with, it worked pretty good. Then I got information overload and started looking for more power so I took out the extra head gasket, yada, yada, yada. Anyway, that didn't work, got pre-ignition crackling and have now completed the circle.
Best, DennisT