Is there any other rear that will work in my '65 barracuda??????

8 1/4 rear is a good one. Mopar Performance told once on the phone that it should tack 400 horse. It will bolt in, but it will have the bigger bolt pattern. I had an 8 1/4 rear in my car for a little bit. I went 8 3/4, but it's not that there was anything wrong with the 8 1/4. I was just after the dump out the front.