Turbocharging a 12 port is no more trouble than a stock head.
Since you have a bump port and a spa exhaust.
With what you have just add a thin divider to the bump port head 1/8 inch wide to the shape of the port tack weld and epoxy seal to the port which can be removed anytime you need to remove the head just a very very thin ribbon of epoxy to seal is what will help. Also if you can divide the intake port this will also help, you want to keep the cylinders from effecting each other so the longer the better.This setup should be good for 400+ HP
Thinking about your bolt in bump maybe you could weld the divider to the bump before installing it, but seal it to the port.
Maybe the guys making bolt in bumps may think about this as an option the divider as part of the bump? Nope this won't work because you need to bolt down the head. But you could add a tube to the divider and bump and use a normal bolt or stud, I have done this in the past it's just the tube has to be the exact length to work. Also I have bolted the bumps through the port side, then they can be removed with no trouble.
