Mopar 383 with 440 crank!
Get a 451 stroker crank (440 w/400 mains, same thing) its probably cheaper now than getting the mains turned down on a 40 year old crank. Youll need to clearance the block too if the throws are too big but I think the cast stroker cranks address that and use 383 size throws, .200 smaller than 440's. Dont know if KB makes an inexpensive shelf stroker piston for that app, but Im sure someone does.