The model is a conversion of Jim Newman's "Strikemaster" design from the '70's. It was originally meant to have a glow 40 in the nose. My WeMoTec Midi fan fits very nicely into the fuselage at the trailing edge. Adding inlets to the flat sides of the fuse is no problem. I can also easily widen the rear end as needed, but didn't want to alter the original design any more than necessary (ie; end up with a flying stovepipe). The 80% to 85% you suggest is easily done, just not quite a sexy. It''s gotta fly well tho', so I'll sharpen my pencil open her up a bit. Now, if I could only remember the formula for computing the area of a circle....
Thom