Just a word of caution, those early heads (and that looks like the 500 head) weren't designed for 1.5" valves.
I big valved my own race twin port head (a previous owner had ported it to 30mm
) and although with a plasticene build had clearance, in practice I had valve clipping issues and had to have the exhaust seats reduced so I could fit smaller exhaust valves. (I bent several valves)
I don't have the measurements to hand but recall my big inlets were more like 1.454 rather than 1.5"
I would suggest you run it with smaller valves and keep the ports on the small side if a road motor.
Opening up ports reduces flow at lower throttle settings. Big ports are for race motors where the throttle is wide open
all the time...
Sort out the fins,
make sure your valves, collets, guides and springs fit.
But once you start opening up ports and valve sizes, its very hard to put the metal back and you may find it goes very well without the big valves.