Did the head ever not have valve stem guides and used just the cast iron hole as a guide? I have a 3614850-5 head. The exhaust valve guides need to be replaced. All valves have some wiggle to them and no longer seal. The exhaust valves themselves look new. Cyl 3 & 4 exhaust valves from what I can tell, have no transition to an installed guide. All other guides have a transition line on both intakes and exhausts. Some guides also are a bit recessed below the cast iron head, others protrude up a bit. Some are flush but you can see the transition. Not 3&4 Exhausts. All exhaust valves are spiraled at the bottom third of the guide.

Just learned from a machinist on YT that the spiral portion on a valve guide needs to be on the spring side, not on the combustion chamber side. So not done correctly in my case I guess.

Most likely if it DOES have "installed guides" the head has been thru the machine shop. Original from the factory they just used the head casting itself for the guide. I have 4 /6 heads here. The only one so far that has guides in it is the one I bought fresh from the machine shop. I'm hoping that the head that is currently in the machine shop comes back with them.

I bought the fresh rebuilt head from CL, had been in a guys basement all wrapped in plastic for 30 years by seller's estimate.
Clearly not from same machine shop that my ported head currently sits.

Thanks. It then looks like only some guides on this head were done. AND the 6 exhaust ones that were done, were done with the guides in backwards.