Yes, same basic frame dimensions, that changed in 67. Inner fenders, not positive but I would say they the front one bhind the wheel is, the one in front of the wheel may be slightly different but I bet it will work.
At the fall ball I saw a 65 Dart with a B motor and it looked tight, then I saw a 66 Dart and I'll be damned if that B motor didn't look like it came from the factory in there.