Originally Posted by Jaybird69
Can I simply connect the black from the chord to both the red and black in the junction box?...
Well that depends of whether you already have a transfer switch between the four wire and the panel. If you do, yes you can connect the red and black together, white to white and green to ground.
Are you planning on doing this permanently or by using a cord and plug? If it is the latter and you have a transfer switch then you need a male on the box and a female on the generator cord, otherwise you have a hot male connector coming from the generator.