Is a Valve Job Necessary/Worth It?
 

So I have the head off my engine to do a head gasket change. While the head is off, I've been debating whether to get a valve job or not. My local shop says a full valve job is $225. Is this absolutely necessary? The engine has about 125k miles on it. Will it be fine for like another 20k miles? Or should I get it done while the head is off. The car is still N/A with plans to boost in the future.

Check the Valves for play and look for their visual condition. Port Vacuum test and if everything is alright call it a day

Tear down the head and inspect. You wont know until you do.

Valve guides are an important wear item to get inspected and replaced if necessary.

Miata valves will go forever, even after heavy valve stem leaks. Are you leaving a little power on the table? Probably. Will it start smoking on cold start after a couple of days of sitting? Probably. Will it run another 100k without it? yup

Valve job
 

$225 is cheap! Most times it's $350-400.

Yeah, i was quoted 350 for it.... I passed because I didn't quite see the point yet.