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I just got my head back from the machine shop - machined mating surfaces and complete valve job. Good guys at the shop - apparently unorganized as they forgot to put two of the jam nuts back on the valves - 3rd cylinder, intake side. Dumba$$ me didn't even realize it. Put the head back on, test drove, didn't notice anything until about 20 mins into the drive and then loud valve rattling noise. Pulled the valve cover off and then kicked my own butt for not checking the head over.

I'm assuming I haven't caused any valve damage? Neither valve stud looks like it's sticking out any further than the others, so I'm assuming I can get two jam nuts, thread them on, perform a complete valve adjustment and rock and roll? Also, do I need to get the $1.70 per each jam nuts from Honda, or will any high-strength 8mm nut work? If I change these two, should I change out the rest?

Thanks for all the help!