cylinder head swap

[ram33]

while removing the engine to repair sprag i noticed down the inlet hole that one of the valve guides has a chunk broken off. ive looked inside cylinder with boroscope but cant see any bits or damage so maybe it passed through or was repaired in he past?
im not sure if i want to risk it so while engine is out i may swap the head if i can find a cheap one.
my question is, i understand that the heads are the same on all the 900 carb triumphs, but does that include the cams and valves or just the casting?

i may also see if i can get a price for replacing one guide but will prob be more than a used head