'65 Barracuda with a '71 340 needs a Radiator...

1.Get a 18in or 20in flex fan,
2.check your pulley sizes cause they are bigger ones and smaller ones,
3. get the fan as close as you can to the radiator so it can pull as much air, there are cheap spacers at A.Z or O.R
4.then just buy a champion radiator and run the later 318 water pump to match the bottom outlet, your going to have to drill it to fit but its not hard.

I have run this set up in Early a bodys and later abodys and it Works well, i have trouble even getting warm.
yes they do make early a body metal shrouds i ran the factory set up with shroud and it did not keep my car as cool as the flex fan champion set up.