Sorry, no clue on the 65's. All that will tell you if the rear end id the same parts as the front end is. Hey listen, not to bust you but the car came with a slant 6 according to a character in your vin and in the fender tag. At this point it's a moot point. You bought a pretty nice car for not much money and it now has a V8 in it. The hard work is done. Is it a 273 or a 318? drive it and enjoy!