Ford 9" in 1965 Barracuda...an option?
Barracuda65, you did not say the width, but I think the Bronco rear end will need shortening on both sides of the pumpkin to fit the Dart, the Explorer rear will need shortening on only one side (although some people run them in the Dart as is, with different offset rims), and the Ranger rear end should be the correct width.
I don't know if the Ranger's correct width means the pumpkin is in the correct place for the Dart though; it may be offset compared to the Dart's transmission / driveshaft tunnel.
What's the gear ratio in the Bronco rear end? Is it what you want?