I have always counted on what I leaned using Manual flash with a Honeywell Strobonar and then Vivitar 283's with my F2 series bodies way back when. Shooting in Manual exposure mode with the flash in Auto mode the results should be much more predictable than shooting in Aperture priority mode. In Manual exposure mode you are using the flash to provide the required power for a correct exposure. In Aperture priority mode the camera's meter is basing the exposure on the ambient light without regard for the flash and the flash is providing additional light based on the light reflected off of the subject. Two seporate systems that are not working together but each on its own. Therefore the possibility of overexposure is more acute. This can be countered by adding some exposure compensation in the camera.
Without knowing the experience level of the Poster I think it is better to provide the "old school" answer than have the user encounter problems down the road based on settings that may not work in all conditions and not understand what the problem is. Good Luck and Enjoy your Nikons!