looking for a real fm3 demon 340 1971.

The only source I believe to be credible would be Galen Govier, at a cost of course. Then again he will only give you the breakdown for your specific vehicle, and yet I'm not sure if he himself has the data to do this, as he specializes in Hemi cars, B and E bodies.
Like the old saying goes "You gotta pay to learn" (so far unfotunately)