engine LA or A

i have a 65 plymouth fury for some reason the years of the first poly to my poly cross each other at my year or so.how can i tell for sure what i have in mine i have the canted valves not all in a row.thats all i know where do i find the numbers on the block to tell me what i have .also how can i tell if this is the motor that came with my car. View attachment 139226
Author: t57f100