Besides the price of converting the car over to BB (as mentioned earlier), a 440 is the cheapest stroker motor to build IMO...and you'll always have more power/torque with the 440.

1967 Satellite, CNC Eddy Headed 500ci Street Mauler
(Dyno'ed @ 600 HP / 650 ft-lbs)

2016 Challenger Hellcat - Holy Hell
2012 Hemi Ram Sport Crew Cab
2011 Avenger, Pentastar V-6
2007 SRT-8 Charger (Dyno'ed @ 470 RWHP)
1986 Caravelle, 318, aka "Rosco", Back Road Burner!

ALL Black...Bad Boys always wear Black!