Fresh, original 72 350 w busted valve keeper - how bad?

[DeadheadNM]

Had the original 350 in my 72 Blazer rebuilt under 600 miles ago by a reputable then local machine shop that's been in business for decades. Character of the idle abruptly changed and an accompanying ticking sound developed. Turns out a valve keeper sheared in half and there's a chip in the top of the corresponding valve.

Not sure why this failed. Whats the likely remedy? Pull the motor, yank the head, and replace the valve? I've got the Blazer at a good local mechanic where I now live. Trying to educate myself ahead of the upcoming "next step" discussion to getting back on the road.