This is a Honda CT90 trail bike from the 70's? Looked up your first post.
Keep all your posts in this one. Makes it easier to follow.
On 911's the shaft of the valves can wear under size. The benefit of new guides is undermined if the valves don't fit in there snug to allow heat transfer into the heads (that have the cooling fins
)
How are you going to do the guides. Do you just press out the old and press in new? There should be some floating reamer or burnish procedure?