One can wiggle them for an idea. But a modern valve job has to have perfect guides to be of any quality. So honestly, it's not even worth me checking. I just budget for guides or liners.
I fully agree with Moper; part of properly redoing a head IS new guides. Years ago when I was Dealer ship wrench we would send heads out to be knurled to save $ and slow oil burning on used cars.
Now a days with Viton seals and bronze guides; you can have a tight valve shaft tolerances and valve seals that last! I like bringing iron heads to the machine shop- for an older auto machinist, these old Chrysler heads are a walk down memory lane. I've even asked them if they had any old Chrysler heads and have come home with more than one set of good heads cheap (beer money!) Ya just gotta ask.
