my 1956 dodge postal van

well i got my RV , but barely . the woman was'nt returning calls to my friend or myself . i was taking the tractor down the road to do some work for a friend and what did i see ? a bunch of people around the RV . i stopped in and told the woman that i had been calling her because i wanted to buy it . she told me that they were pulling the generator and going to haul it to the junkyard , but if i wanted it i could have it for the $250 .

i have googled trying to find what engine size might be in it , but apparently they came out with anything from a 318 to a 440 . can anyone tell what engine this might be from the pics ? can anyone tell me where to find the numbers on the block ?

its a 1977 dodge sportsman with 64,664 miles on it .

mike