I have got a hole in my radiator the leaks faster them i can fill it. is the are another model car that interchange it with
Measure it and make a trip to the junk yard......you may even have to make a few modifications to make one fit. I would go with about the same width or a little wider. Good Luck
It's usually not worth the trouble you go thru in trying to find and using a used radiator, especially if it's as old as the car already is. Most radiators that are 30 plus years old are likely to leak or be on the verge of it. Check the parts stores or your local radiator repair shop. You should be able to get a new one for $150-$200 and your troubles will be over...with no modifications.
I agree with Ray, the 2 core stock radiators are available from most auto parts stores brand new. You can also pick up a 3 core radiator for a 1970 Mustang with a 302 from any Mustang parts house, and it is a direct bolt in (just looks a little different).
I had mine re-cored last year, the shop used a core that has twice the passes in the same area as the original had one, it was about $250.