That looks alittle bit like mine



I wouldn't go shaving too much off it though
Piston choice will give you compressions. Don't just shave the head down. Cause once the metal is gone its gone. Have a head issue and you'll need to start looking for another
Just deck it enough to get a nice straight face
Same with the ports. If its a street motor don't hog them out too far
Big ports don't breathe well down low as they need gobs of air . Small ports give more airspeed and driveability.

Pick the right pistons, cam and carbs and you can make good HP and still keep it driveable
My engine made 100 hp atw with 9.0:1 comp , small ports and stock deck.