Been there done that with big valve ported 906 heads on many stock stroke 440
My pump gas Duster motor last configuration was a 400 block with a 4.300 stroke crank and 4.375 bore with 10.7 to 1 compression, Indy M.W. port SR heads, 400-3 intake with a Holley #9375 non HP 1050 CFM dominator,Custm ground Comp Cams solid roller cam, it made 727 HP the last time it was on a engine dyno on pump gas
I did swap the heads on it from the iron heads to a set of CNC ported Eddy RPM and then to set to CNC ported 440-1, the motor made 775 HP with them and the last set was the SR that made 727 HP
Every time I fed that motor more air and fuel it went faster and made more power on the engine dyno and chassis dyno
I drove it on the street some, 3000+ miles in 7 years, I raced it more than driving it on the street though, it was not my daily driver
On your deal I'm sure you will make more than 650 HP with no sweat
My Duster weighed 3450 Lb. with me in it, it was a hoot to drive on the street