'57 Dodge Custom Royal Lancer

Could one put a la forged crank 318/340 into a dodge 325 poly with longer rods?


No, they are completely different motors, and the Dodge's bore spacing is way smaller than the A/LA. The early (53-58) Dodge hemi/poly has one of the smallest - if not the smallest - bore spacings (distance between the bores) of any modern American V8.