"power valve = 8.5 ( BTW, @ 3-5" yours is open ( dumping fuel )all the time -" This is what is was thinking and would make it terrible out of the gate but ok top end since you want all that gas. FWIW I made the mistake using a 509 in a stock 72 440 once. I used a 750 holley vacuum carb and it never ran right due to the poor vacuum signal that cam makes. Now full throttle on the highway, no problem. Check your PV...make sure you have the right one.
