Duster Idiot has the process down pat.

Depending on what machine shop is available....

The nearest (2.5 hours) , best machine shop near me was very Chevvy and afraid to do a slant head (69 drool tube) .

I sent the head to them with a complete set of 1.72/1.50 chev valves , springs, retainers, keepers. All very cheap and available in sets.

I had done all my port work ....but left the bowls. We used a vertical mill to radius around the valves.

I got the machine shop to bowl hog, valve grind, mill valve seats , and install valve gear .....like a chev v8. They have all the tools and expertise for that . It worked out fine.

I ended up with free seats. I think they are more trouble than value.

Keep valve stem size in mind when you order.