Drivetrain advice for engine swap

I apologize for the mis-info...I know better then to repeat what I'm told til I verify it.. but didn't this time. My neighbor built a Cobra and he said he used a 9'' Explorer rear with discs, so I find he was misinformed as well. I have used 9'' in dirt track cars, had them cut to fit and axles resplined for $135.00, but that too was 10 years ago. And thank you all for setting me straight.