I just installed the Johnson last weekend, yes it does fit ! although it needs a little work to do it.
I removed the connector from the old pump, and soldered it to the Johnson wires, it's marked + and _ (as per 32krazy, thanks for the tip), removed the pump bracket completely, drilled a new hole and mounted the pump with the supplied Johnson bracket. Use worm drive clamps on the inlet and outlet, and you're done.