So Thunderchief and I made several checks on the plane. We found that the wing, stab and motor thrust is all at a very nice +1.0 degrees. This practically leaves only the CG to blame.

If I move the CG back as I stated above, it will be behind the fuel tanks. This effectively generates a different CG for dry (no fuel) vs wet (full fuel load).

Those numbers are as follows, if I target half a fuel load as the center-line:
Dry, the CG would comes out to 33% MAC and wet would be 23% MAC. This is too large a swing in my opinion. But I am not an Interceptor expert (yet)...

Would some of you please chime in? Is this too much of a swing for this plane?