I love this stuff!
Assuming that the width across the valves is the actual bore size, yes?
Just a few ideas, none necessarily useful:
1. if you have enough head deck thickness (hate to cut up a vintage race piece, but... that's what it was made for), or block deck thickness a big angle mill cut acrossto make a wedge and give some intake valve axis tilt into the bore. Obviously, spot face the bolt seats, re-drill the holes slightly for clearance etc.
2. more width on the siamese intakes
3. more intake height for some downdraft
4. close up the chamber opposite the plug. Easiest shape to plan is a heart (red area), also gives quench with a flat piston
5. if that exhaust notch is really needed, also relieve the cylinder wall
6. more rocker ratio
What did you have in mind for carbs?