I put a 65 Mustang 289 radiator in my 71. The mounting points are the same, too. The radiator itself is about 3 inches taller, and all that extra height is on the bottom, so the hood clearance isn't affected. I'm running a 2.3 turbo in mine, so I did have to make up some radiator hoses so it would work. The upper was kinda tricky, but I got a universal type at the parts store that has a molded in 90* bend that helped a lot. The lower was easy to make. I used a portion of some lower hose I had laying around, and it really could not have fit any better. The radiator itself is all brass or copper, so it looks the way it should, but the actual core is about twice as thick and it has a lot more fins on the outside. It's been working pretty well now, even here in FL during July and August, but it's not perfect. I keep the fan on all the time (a slim electric pusher between the intercooler and the rad), and try to run it almost too cool all the time (I don't have a T-stat either, but an aluminum plate with a 5/8" hole drilled in it). Fitting the thing in there WAS a chore because the core is much thicker, and the 2.3 isn't the right engine for that year anyway. The water pump pully is about 1/4" or less (seriously) from the radiator. I beat the bejeezus out of the car, so I know that the clearance I have IS sufficient, but it was so close putting it together that I had to remove that spacer on the water pump and get some shorter bolts, too.
I really, really wish I had started with a car that a 2.3 to begin with.