here is the gig....
if that head has had guide replacement and it was not done correctly
and IF even one guide bore is crap
and all you have to do is look with your eyes first......... if you can see crap it's crap
the guide bore should be smooth, any galling or gouging in the bore means the casting is NFG
I wouldn't waste my shipping money if the guide bores are shot
and anyone that knows what is involved to repair a bad valve guide bore will tell you just to get a good casting
if the bores look good.... then it's ok to send the head out and hope the shop getting it will make sure they are also good and round
you can knock the guides out cold but they come out butter easy if you warm the head
best is to blast the port sides of the guides to make sure they are clean before you press or knock them back out the guide bore
here is a tool that is very afforable for pressing guides in or out cold
you can also use an air hammer with a piloted punch and either method will work cold with no damage done
just don't try to knock them out sideways