I went and got a piece of plywood from home depot and cut about a 1/3 sized back that sits in the middle third of the cab so the top third and bottom third are open. I did this to use the center brace.
i removed the stock mono/stereo switch and the thin 22 ga wire. I hardwired 16 ga wire to a new jack plate and soldered all the connections.
That alone was an improvement.
Open back really added a 3D sound. I thought the golds sounded stifled in a closed back. It sounded much bigger as an open back, the sound fills the room much better. Like the sound surrounds you instead of punching you in the gut