So, methinks the gag will be to raise the roof of the port a little. And build up some JB Weld between the spring seats. Try to straighten things out without making to thin a port wall between the ex port and the oil.
Then open up the restriction at the exit (donut).
Then taper the valve guide and guide boss on the port side.
And fill up some of the valleys in the ex port to lose the speed bumps.
Have this high temp epoxy from Manley that is designed to be used in exactly this application.
One way to find out