The 413 and most of the 1963 M.W. motors where stage 1 motors, mid year in 1963 Mopar came out with the Stage 2 425 HP motor that had the same carbs and camshaft as the 425 HP 1964 M.W. came with.
All the 1964 M.W. motors where considered and called Stage 3 is what I remember from back then
I think all the 1963 cams where considered 300 degree total duration with right at .509 lift, the 1964 415 HP motors had a little more duration, either 312 or 316 degrees advertised with around .510 lift at the valves and the 1964 425 HP motors had the biggest wedge made for production cars with 320 degrees advertised duration and right at .520 valve lift
All the Mopar ductile iron rocker arms I've check where no where near perfect, most didn't meet the 1.5 ratio, always less