I have been working on my 81 CJ-7 over the winter to swap out the stock axles and install Dana 44's w/ rear disc brakes. Over the course of the winter I have periodically started her up and let her run and she idles fine. I recently finished the conversion and took her out for a spin. While I was testing the brakes I was lacking power. There is a whistling coming from the carb when I give her gas and when I got back from the ride there was milky oil sprayed against the top of the air cleaner and inside the carb. The previous owner installed a holley double barrel carb in it. Any suggestions?

Do you mean when applying brakes the idle dropped off or the brakes had no power?
Milky oil is usually condensation in the crankcase. As your engine heats up it should go away after a while. Check for vacuum leaks and the PCV valve maybe?
Josh