ha!
I thought it was 6.25... even better
Either way, you should be good on the back end, but you'll probably have to pull the curved liner off of the door to accomodate the knob in the front... unless you mount the unit on the bottom or mod the liner/insert
...who knows? it may even clear the knob, but I would go with melting the liner a bit (if needed) and keeping the head unit on the top side.